| Seq | Timestamp | Type | Name | Duration |
|---|---|---|---|---|
| 0/0 | 2026/09/09 21:12 | flow | patch-triage |
1mArgs:null Results: {
"EnableConfigs": [
"KERNFS"
],
"FocusSymbols": [
"sget_fc",
"put_super",
"deactivate_locked_super",
"generic_shutdown_super",
"kill_anon_super",
"kernfs_kill_sb"
],
"KMSANReasoning": "The patch modifies the lifecycle management and synchronization of superblock instances (fs/super.c and fs/kernfs/mount.c) across mount and shutdown paths (sget_fc, kill_super_notify, put_super). It defers unlinking sb-\u003es_instances and put_filesystem to put_super, while holding sb_lock when setting SB_DEAD so concurrent sget_fc() calls skip dying superblocks.\n\nThese changes deal strictly with reference counting, locking (sb_lock), list management, and object lifecycle synchronization. Any potential regressions or bugs introduced here (such as use-after-free, race conditions, or locking issues) are tracked by KASAN, LOCKDEP, and standard kernel debugging facilities. No uninitialized memory, buffer parsing, or kernel-to-userspace copying is introduced or modified. Therefore, a dedicated KMSAN fuzzing session is not warranted.",
"NeedsKMSAN": false,
"Reasoning": "The patch modifies core VFS superblock lifecycle and concurrency management across mount and unmount paths (in fs/super.c and fs/kernfs/mount.c). It defers unlinking superblocks from fs_supers until the last passive reference drops in put_super(), sets SB_DEAD under sb_lock in kill_super_notify(), and skips SB_DEAD superblocks during sget_fc() traversal. These changes alter concurrency invariants between concurrent mount (sget_fc) and shutdown/deactivation routines, making this core subsystem code well worth fuzzing for synchronization and reference counting regressions.",
"WorthFuzzing": true
} |
| 1/1 | 2026/09/09 21:12 | action | read-patch-diff |
0mArgs:null Results: {
"PatchDiff": "commit c9c7f033e1743e33ebdeb8b896db27baf54d70a8\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Wed Sep 9 21:12:32 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c\nindex f183a96778b9a..a57399021c8b0 100644\n--- a/fs/kernfs/mount.c\n+++ b/fs/kernfs/mount.c\n@@ -434,8 +434,8 @@ void kernfs_kill_sb(struct super_block *sb)\n \tup_write(\u0026root-\u003ekernfs_supers_rwsem);\n \n \t/*\n-\t * Remove the superblock from fs_supers/s_instances\n-\t * so we can't find it, before freeing kernfs_super_info.\n+\t * Mark the superblock dead so sget_fc() can't find it,\n+\t * before freeing kernfs_super_info.\n \t */\n \tkill_anon_super(sb);\n \tkfree(info);\ndiff --git a/fs/super.c b/fs/super.c\nindex 05e4431730387..0f9e13eedb4fb 100644\n--- a/fs/super.c\n+++ b/fs/super.c\n@@ -433,15 +433,19 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags,\n void put_super(struct super_block *s)\n {\n \tif (refcount_dec_and_test(\u0026s-\u003es_passive)) {\n+\t\tstruct file_system_type *type = s-\u003es_type;\n \n \t\tspin_lock(\u0026sb_lock);\n \t\tlist_del_init(\u0026s-\u003es_list);\n+\t\thlist_del_init(\u0026s-\u003es_instances);\n \t\tspin_unlock(\u0026sb_lock);\n \n \t\tWARN_ON(s-\u003es_dentry_lru.node);\n \t\tWARN_ON(s-\u003es_inode_lru.node);\n \t\tWARN_ON(s-\u003es_mounts);\n \t\tcall_rcu(\u0026s-\u003ercu, destroy_super_rcu);\n+\t\t/* The unlink above may touch type-\u003efs_supers, so drop it last. */\n+\t\tput_filesystem(type);\n \t}\n }\n \n@@ -558,17 +562,6 @@ static void kill_super_notify(struct super_block *sb)\n \tif (sb-\u003es_flags \u0026 SB_DEAD)\n \t\treturn;\n \n-\t/*\n-\t * Remove it from @fs_supers so it isn't found by new\n-\t * sget_fc() walkers anymore. Any concurrent mounter still\n-\t * managing to grab a temporary reference is guaranteed to\n-\t * already see SB_DYING and will wait until we notify them about\n-\t * SB_DEAD.\n-\t */\n-\tspin_lock(\u0026sb_lock);\n-\thlist_del_init(\u0026sb-\u003es_instances);\n-\tspin_unlock(\u0026sb_lock);\n-\n \t/* Drop sget_fc()'s claim; a never-registered entry stays with the sb. */\n \tif (sb-\u003es_super_dev-\u003esd_dev) {\n \t\tsuper_dev_put(sb-\u003es_super_dev);\n@@ -577,11 +570,15 @@ static void kill_super_notify(struct super_block *sb)\n \n \t/*\n \t * Let concurrent mounts know that this thing is really dead.\n-\t * We don't need @sb-\u003es_umount here as every concurrent caller\n-\t * will see SB_DYING and either discard the superblock or wait\n-\t * for SB_DEAD.\n+\t * sget_fc() skips SB_DEAD superblocks and calls test() under\n+\t * sb_lock, so set it under sb_lock: once we return no test()\n+\t * runs on this superblock anymore and none will start. Everyone\n+\t * else already saw SB_DYING and either discarded the superblock\n+\t * or waits for SB_DEAD.\n \t */\n+\tspin_lock(\u0026sb_lock);\n \tsuper_wake(sb, SB_DEAD);\n+\tspin_unlock(\u0026sb_lock);\n }\n \n /**\n@@ -608,7 +605,6 @@ void deactivate_locked_super(struct super_block *s)\n \t\tlist_lru_destroy(\u0026s-\u003es_dentry_lru);\n \t\tlist_lru_destroy(\u0026s-\u003es_inode_lru);\n \n-\t\tput_filesystem(fs);\n \t\tput_super(s);\n \t} else {\n \t\tsuper_unlock_excl(s);\n@@ -795,12 +791,12 @@ void generic_shutdown_super(struct super_block *sb)\n \t}\n \t/*\n \t * Broadcast to everyone that grabbed a temporary reference to this\n-\t * superblock before we removed it from @fs_supers that the superblock\n-\t * is dying. Every walker of @fs_supers outside of sget_fc() will now\n-\t * discard this superblock and treat it as dead.\n+\t * superblock that it is dying. Every walker of @fs_supers outside\n+\t * of sget_fc() will now discard this superblock and treat it as\n+\t * dead.\n \t *\n-\t * We leave the superblock on @fs_supers so it can be found by\n-\t * sget_fc() until we passed sb-\u003ekill_sb().\n+\t * sget_fc() keeps finding the superblock until SB_DEAD is set, so\n+\t * a concurrent mounter waits until we passed sb-\u003ekill_sb().\n \t */\n \tsuper_wake(sb, SB_DYING);\n \tsuper_unlock_excl(sb);\n@@ -879,6 +875,9 @@ struct super_block *sget_fc(struct fs_context *fc,\n \tspin_lock(\u0026sb_lock);\n \tif (test) {\n \t\thlist_for_each_entry(old, \u0026fc-\u003efs_type-\u003efs_supers, s_instances) {\n+\t\t\t/* Only unlinked at the last passive reference. */\n+\t\t\tif (super_flags(old, SB_DEAD))\n+\t\t\t\tcontinue;\n \t\t\tif (test(old, fc))\n \t\t\t\tgoto share_extant_sb;\n \t\t}\n"
} |
| 2/1 | 2026/09/09 21:12 | agent | patch-evaluator |
0mModel:core Args: null Results: {
"EnableConfigs": [
"KERNFS"
],
"FocusSymbols": [
"sget_fc",
"put_super",
"deactivate_locked_super",
"generic_shutdown_super",
"kill_anon_super",
"kernfs_kill_sb"
],
"Reasoning": "The patch modifies core VFS superblock lifecycle and concurrency management across mount and unmount paths (in fs/super.c and fs/kernfs/mount.c). It defers unlinking superblocks from fs_supers until the last passive reference drops in put_super(), sets SB_DEAD under sb_lock in kill_super_notify(), and skips SB_DEAD superblocks during sget_fc() traversal. These changes alter concurrency invariants between concurrent mount (sget_fc) and shutdown/deactivation routines, making this core subsystem code well worth fuzzing for synchronization and reference counting regressions.",
"WorthFuzzing": true
}Instruction: You are an expert Linux kernel maintainer and security engineer.
Your job is to review a provided patch series and evaluate whether it warrants fuzzing with syzkaller.
IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in
your workspace. Do NOT rely on internal assumptions. You must actively use your code access
tools to inspect the actual source code, callers, and surrounding context.
================================================================================
1. CORE TRIAGE PHILOSOPHY
================================================================================
The goal of patch fuzzing is to discover crashes, regressions, exposed latent bugs,
and newly triggered assertions introduced by the patch series.
- REACHABILITY IS THE PRIMARY GATE:
Fuzzing can only discover bugs in code that can actually execute in standard virtualized
environments (GCE or QEMU, utilizing software-emulated devices like USB gadgets, netdev, tun/tap).
If the modified code is structurally unreachable (see Section 2), it MUST NOT be fuzzed,
regardless of whether it adds assertions or complex logic.
- DO NOT BLINDLY TRUST "NO FUNCTIONAL CHANGE" (NFCI) OR "REFACTORING" CLAIMS:
Patch authors routinely label changes as "cleanups", "refactorings", or state
"No functional change intended". Do NOT take these claims at face value.
Code refactorings that rearrange logic, introduce helper functions, or alter state management
in core subsystems frequently introduce subtle semantic shifts or uncover latent kernel bugs.
If reachable executable code is modified or refactored, it MUST be fuzzed.
- NEW OR MODIFIED ASSERTIONS IN REACHABLE CODE MUST BE FUZZED:
When a patch introduces or modifies runtime checks or assertions (e.g., WARN_ON*, VM_WARN_ON*,
BUG_ON*, lockdep_assert*) in reachable code paths, it enforces new or stricter invariants.
Even if the author believes the invariant always holds, fuzzing is essential to verify whether
an unusual sequence of operations can violate it.
================================================================================
2. WHEN TO RETURN WorthFuzzing=false (NEGATIVE CRITERIA)
================================================================================
Return WorthFuzzing=false ONLY IF all modified code falls strictly into one or more of these categories:
- Non-kernel and non-executable changes:
* Modifications to Documentation/, comments, or spelling fixes.
* User-space directories, self-tests, samples, or scripts (e.g., tools/, samples/, scripts/, usr/)
that do not affect the compiled kernel image (vmlinux) or kernel modules.
* Purely decorative logging (e.g., message strings in pr_err, printk, dev_info) or tracepoints
that do not alter control flow or data structures.
* Build system or Kconfig changes that do not alter compiled C logic.
- Structurally unreachable hardware:
* Vendor-specific PCIe switches, SmartNICs, or GPU drivers (e.g., mlxsw, pds_core, qed,
ionic, amdgpu) requiring physical ASIC/PCIe cards not emulated in standard QEMU.
- Unreachable execution paths:
* Driver teardown callbacks (.remove, .shutdown, pci_unregister_driver) executed only during
physical PCI hot-unplug or manual sysfs driver unbinding.
* Code paths exclusive to architectures other than the target architecture.
================================================================================
3. WHEN TO RETURN WorthFuzzing=true (POSITIVE CRITERIA)
================================================================================
Return WorthFuzzing=true whenever the patch touches reachable executable code, including:
- Core Subsystems:
* Any logic modifications in memory management (mm/), synchronization/locking (kernel/locking/),
BPF, scheduler, core networking, VFS, or syscall handling.
- Refactorings and Code Cleanups:
* Any restructuring of reachable data structures, helper abstractions, or algorithm flows.
- Runtime Assertions and Defensive Checks:
* Any introduction or alteration of assertions (WARN_ON*, VM_WARN_ON*, BUG_ON*, etc.) in reachable paths.
- Reachable Drivers and Protocols:
* Drivers accessible via virtual buses (virtio, USB gadget, loopback, netlink, binder, sockets, etc.).
================================================================================
4. EXTRACTING FocusSymbols (PREVENTING DILUTION)
================================================================================
When WorthFuzzing=true, you must extract specific kernel functions into FocusSymbols to guide the fuzzer:
- AVOID UBIQUITOUS LIFECYCLE HOT-PATHS:
Do NOT list generic, ubiquitous functions called by almost every program in the corpus
(including, but not limited to: general memory allocators and deallocators, page fault
and trap handlers, or core synchronization primitives; this is not an exhaustive list).
Listing ubiquitous functions causes the fuzzer to classify thousands of unrelated tests as "focused",
which severely dilutes fuzzing effort away from the actual changes.
- TARGET SPECIFIC FEATURE LOGIC AND ENTRYPOINTS:
List functions that specifically implement the logic being added or altered, or direct API entrypoints
for the subsystem feature under review.
- HANDLING STATIC INLINE FUNCTIONS IN HEADERS (.h):
Compiler-inlined static functions (such as static inlines in mm/*.h or include/linux/*.h) lack
distinct symbol addresses in vmlinux and cannot be targeted directly by symbol coverage filters.
If the changes are primarily in static inline helpers, identify non-static, feature-specific caller
functions in .c files that exercise them (avoiding ubiquitous lifecycle wrappers).
================================================================================
5. IDENTIFYING EnableConfigs
================================================================================
Identify any specific CONFIG_ options required to properly compile and reach the modified code:
- Inspect Kconfig files and #ifdef guards; do not make assumptions.
- Check "depends on" lines in Kconfig to include any non-standard parent subsystem configs needed.
- Strip any 'CONFIG_' prefix (e.g., return "NET_IPV4" instead of "CONFIG_NET_IPV4").
Prefer calling several tools at the same time to save round-trips.
Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.
Prompt: Target architecture: amd64
For your convenience, here is the diff of the changes:
commit c9c7f033e1743e33ebdeb8b896db27baf54d70a8
Author: syz-cluster <triage@syzkaller.com>
Date: Wed Sep 9 21:12:32 2026 +0000
syz-cluster: applied patch under review
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index f183a96778b9a..a57399021c8b0 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -434,8 +434,8 @@ void kernfs_kill_sb(struct super_block *sb)
up_write(&root->kernfs_supers_rwsem);
/*
- * Remove the superblock from fs_supers/s_instances
- * so we can't find it, before freeing kernfs_super_info.
+ * Mark the superblock dead so sget_fc() can't find it,
+ * before freeing kernfs_super_info.
*/
kill_anon_super(sb);
kfree(info);
diff --git a/fs/super.c b/fs/super.c
index 05e4431730387..0f9e13eedb4fb 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -433,15 +433,19 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags,
void put_super(struct super_block *s)
{
if (refcount_dec_and_test(&s->s_passive)) {
+ struct file_system_type *type = s->s_type;
spin_lock(&sb_lock);
list_del_init(&s->s_list);
+ hlist_del_init(&s->s_instances);
spin_unlock(&sb_lock);
WARN_ON(s->s_dentry_lru.node);
WARN_ON(s->s_inode_lru.node);
WARN_ON(s->s_mounts);
call_rcu(&s->rcu, destroy_super_rcu);
+ /* The unlink above may touch type->fs_supers, so drop it last. */
+ put_filesystem(type);
}
}
@@ -558,17 +562,6 @@ static void kill_super_notify(struct super_block *sb)
if (sb->s_flags & SB_DEAD)
return;
- /*
- * Remove it from @fs_supers so it isn't found by new
- * sget_fc() walkers anymore. Any concurrent mounter still
- * managing to grab a temporary reference is guaranteed to
- * already see SB_DYING and will wait until we notify them about
- * SB_DEAD.
- */
- spin_lock(&sb_lock);
- hlist_del_init(&sb->s_instances);
- spin_unlock(&sb_lock);
-
/* Drop sget_fc()'s claim; a never-registered entry stays with the sb. */
if (sb->s_super_dev->sd_dev) {
super_dev_put(sb->s_super_dev);
@@ -577,11 +570,15 @@ static void kill_super_notify(struct super_block *sb)
/*
* Let concurrent mounts know that this thing is really dead.
- * We don't need @sb->s_umount here as every concurrent caller
- * will see SB_DYING and either discard the superblock or wait
- * for SB_DEAD.
+ * sget_fc() skips SB_DEAD superblocks and calls test() under
+ * sb_lock, so set it under sb_lock: once we return no test()
+ * runs on this superblock anymore and none will start. Everyone
+ * else already saw SB_DYING and either discarded the superblock
+ * or waits for SB_DEAD.
*/
+ spin_lock(&sb_lock);
super_wake(sb, SB_DEAD);
+ spin_unlock(&sb_lock);
}
/**
@@ -608,7 +605,6 @@ void deactivate_locked_super(struct super_block *s)
list_lru_destroy(&s->s_dentry_lru);
list_lru_destroy(&s->s_inode_lru);
- put_filesystem(fs);
put_super(s);
} else {
super_unlock_excl(s);
@@ -795,12 +791,12 @@ void generic_shutdown_super(struct super_block *sb)
}
/*
* Broadcast to everyone that grabbed a temporary reference to this
- * superblock before we removed it from @fs_supers that the superblock
- * is dying. Every walker of @fs_supers outside of sget_fc() will now
- * discard this superblock and treat it as dead.
+ * superblock that it is dying. Every walker of @fs_supers outside
+ * of sget_fc() will now discard this superblock and treat it as
+ * dead.
*
- * We leave the superblock on @fs_supers so it can be found by
- * sget_fc() until we passed sb->kill_sb().
+ * sget_fc() keeps finding the superblock until SB_DEAD is set, so
+ * a concurrent mounter waits until we passed sb->kill_sb().
*/
super_wake(sb, SB_DYING);
super_unlock_excl(sb);
@@ -879,6 +875,9 @@ struct super_block *sget_fc(struct fs_context *fc,
spin_lock(&sb_lock);
if (test) {
hlist_for_each_entry(old, &fc->fs_type->fs_supers, s_instances) {
+ /* Only unlinked at the last passive reference. */
+ if (super_flags(old, SB_DEAD))
+ continue;
if (test(old, fc))
goto share_extant_sb;
}
|
| 3/2 | 2026/09/09 21:12 | llm | patch-evaluator |
0mModel:gemini-3.7-flash Args: null Results: null Tokens: input: 4187 output: 26 thoughts: 63 Thoughts: Okay, here's my understanding of the situation, tailored for a fellow expert: **Analyzing a Linux Kernel Patch for Syzkaller Integration** Alright, so the objective is clear: evaluate a Linux kernel patch. Specifically, this one's been flagged for use with syzkaller, which immediately raises my internal red flags. We're looking for potential fuzzing surface and ensuring proper coverage. My first instinct is always to dive deep into the patch itself and its surrounding context. Where did it come from? What's the change trying to achieve? I'll probably start by checking the affected files. A quick look at the `git` history around those files is essential, using tools like `git blame` or `git log` with the relevant `--follow` and `--name-only` options. I need to understand the development history, who authored the code and their prior context. Next step: I'll need to confirm my initial hypothesis on file changes. I'll need to *actually* read the patch, but before I get bogged down in details I may use `git grep` within the changed files to quickly identify key functions, data structures, or interesting variables. This might quickly highlight areas of interest and help to focus the in-depth review, saving time. Alternatively, if the file size is manageable, I could just read the files. |
| 4/2 | 2026/09/09 21:12 | tool | grepper |
0mArgs:{
"Expression": "sget_fc",
"PathPrefix": "fs/"
}Results: {
"Output": "fs/9p/vfs_super.c=82=static int v9fs_get_tree(struct fs_context *fc)\n--\nfs/9p/vfs_super.c-103-\tfc-\u003es_fs_info = v9ses;\nfs/9p/vfs_super.c:104:\tsb = sget_fc(fc, NULL, set_anon_super_fc);\nfs/9p/vfs_super.c-105-\tif (IS_ERR(sb)) {\n--\nfs/afs/super.c=548=static int afs_get_tree(struct fs_context *fc)\n--\nfs/afs/super.c-568-\t/* allocate a deviceless superblock */\nfs/afs/super.c:569:\tsb = sget_fc(fc,\nfs/afs/super.c-570-\t\t as-\u003edyn_root ? afs_dynroot_test_super : afs_test_super,\n--\nfs/btrfs/super.c=1861=static int btrfs_get_tree_super(struct fs_context *fc)\n--\nfs/btrfs/super.c-1885-\t/*\nfs/btrfs/super.c:1886:\t * We cannot hold uuid_mutex calling sget_fc(), it will lead to a\nfs/btrfs/super.c-1887-\t * locking order reversal with s_umount.\n--\nfs/btrfs/super.c-1897-\nfs/btrfs/super.c:1898:\tsb = sget_fc(fc, btrfs_fc_test_super, set_anon_super_fc);\nfs/btrfs/super.c-1899-\tif (IS_ERR(sb)) {\n--\nfs/btrfs/super.c=2061=static int btrfs_get_tree_subvol(struct fs_context *fc)\n--\nfs/btrfs/super.c-2075-\t * of the fs_info (locks and such) to make cleanup easier if we find a\nfs/btrfs/super.c:2076:\t * superblock with our given fs_devices later on at sget_fc() time.\nfs/btrfs/super.c-2077-\t */\n--\nfs/btrfs/super.c-2102-\t/*\nfs/btrfs/super.c:2103:\t * When we do the sget_fc this gets transferred to the sb, so we only\nfs/btrfs/super.c-2104-\t * need to set it on the dup_fc as this is what creates the super block.\n--\nfs/btrfs/volumes.h=341=struct btrfs_fs_devices {\n--\nfs/btrfs/volumes.h-429-\t * after a super block is created. But we cannot take uuid_mutex\nfs/btrfs/volumes.h:430:\t * during sget_fc(), thus we have to hold the fs_devices (meaning it\nfs/btrfs/volumes.h-431-\t * cannot be released) until a super block is returned.\n--\nfs/ceph/super.c=1309=static int ceph_get_tree(struct fs_context *fc)\n--\nfs/ceph/super.c-1343-\tfc-\u003es_fs_info = fsc;\nfs/ceph/super.c:1344:\tsb = sget_fc(fc, compare_super, ceph_set_super);\nfs/ceph/super.c-1345-\tfc-\u003es_fs_info = NULL;\n--\nfs/ecryptfs/main.c=435=static int ecryptfs_get_tree(struct fs_context *fc)\n--\nfs/ecryptfs/main.c-464-\nfs/ecryptfs/main.c:465:\ts = sget_fc(fc, NULL, set_anon_super_fc);\nfs/ecryptfs/main.c-466-\tif (IS_ERR(s)) {\n--\nfs/ext4/extents-test.c=222=static int extents_kunit_init(struct kunit *test)\n--\nfs/ext4/extents-test.c-242-\t}\nfs/ext4/extents-test.c:243:\tsb = sget_fc(fc, NULL, ext_set);\nfs/ext4/extents-test.c-244-\tput_fs_context(fc);\n--\nfs/ext4/mballoc-test.c=137=static struct super_block *mbt_ext4_alloc_super_block(void)\n--\nfs/ext4/mballoc-test.c-151-\nfs/ext4/mballoc-test.c:152:\tsb = sget_fc(fc, NULL, mbt_set);\nfs/ext4/mballoc-test.c-153-\tput_fs_context(fc);\n--\nfs/fuse/inode.c=1676=static int fuse_get_tree_submount(struct fs_context *fsc)\n--\nfs/fuse/inode.c-1689-\tfsc-\u003es_fs_info = fm;\nfs/fuse/inode.c:1690:\tsb = sget_fc(fsc, NULL, set_anon_super_fc);\nfs/fuse/inode.c-1691-\tif (fsc-\u003es_fs_info)\n--\nfs/fuse/inode.c=1853=static int fuse_get_tree(struct fs_context *fsc)\n--\nfs/fuse/inode.c-1897-\t\tfsc-\u003esget_key = ctx-\u003efud;\nfs/fuse/inode.c:1898:\t\tsb = sget_fc(fsc, fuse_test_super, fuse_set_no_super);\nfs/fuse/inode.c-1899-\t\terr = PTR_ERR_OR_ZERO(sb);\n--\nfs/fuse/virtio_fs.c=1681=static int virtio_fs_get_tree(struct fs_context *fsc)\n--\nfs/fuse/virtio_fs.c-1733-\tfsc-\u003es_fs_info = fm;\nfs/fuse/virtio_fs.c:1734:\tsb = sget_fc(fsc, virtio_fs_test_super, set_anon_super_fc);\nfs/fuse/virtio_fs.c-1735-\tif (fsc-\u003es_fs_info)\n--\nfs/gfs2/ops_fstype.c=1673=static int gfs2_meta_get_tree(struct fs_context *fc)\n--\nfs/gfs2/ops_fstype.c-1690-\tfc-\u003esget_key = path.dentry-\u003ed_sb-\u003es_bdev;\nfs/gfs2/ops_fstype.c:1691:\ts = sget_fc(fc, test_meta_super, set_meta_super);\nfs/gfs2/ops_fstype.c-1692-\tpath_put(\u0026path);\n--\nfs/kernfs/mount.c=366=int kernfs_get_tree(struct fs_context *fc)\n--\nfs/kernfs/mount.c-381-\tfc-\u003es_fs_info = info;\nfs/kernfs/mount.c:382:\tsb = sget_fc(fc, kernfs_test_super, kernfs_set_super);\nfs/kernfs/mount.c-383-\tif (IS_ERR(sb))\n--\nfs/kernfs/mount.c=427=void kernfs_kill_sb(struct super_block *sb)\n--\nfs/kernfs/mount.c-436-\t/*\nfs/kernfs/mount.c:437:\t * Mark the superblock dead so sget_fc() can't find it,\nfs/kernfs/mount.c-438-\t * before freeing kernfs_super_info.\n--\nfs/nfs/super.c=1296=int nfs_get_tree_common(struct fs_context *fc)\n--\nfs/nfs/super.c-1316-\tfc-\u003es_fs_info = server;\nfs/nfs/super.c:1317:\ts = sget_fc(fc, compare_super, nfs_set_super);\nfs/nfs/super.c-1318-\tfc-\u003es_fs_info = NULL;\n--\nfs/orangefs/super.c=455=static int orangefs_get_tree(struct fs_context *fc)\n--\nfs/orangefs/super.c-489-\nfs/orangefs/super.c:490:\tsb = sget_fc(fc, NULL, set_anon_super_fc);\nfs/orangefs/super.c-491-\n--\nfs/smb/client/cifsfs.c=990=cifs_smb3_do_mount(struct fs_context *fc, struct smb3_fs_context *old_ctx)\n--\nfs/smb/client/cifsfs.c-1042-\t * ignored the caller-supplied SB_* flags. Preserve that behaviour by\nfs/smb/client/cifsfs.c:1043:\t * overriding fc-\u003esb_flags around the sget_fc() call.\nfs/smb/client/cifsfs.c-1044-\t *\nfs/smb/client/cifsfs.c:1045:\t * Hand cifs_sb to sget_fc() via fc-\u003es_fs_info; sget_fc() copies it\nfs/smb/client/cifsfs.c-1046-\t * onto sb-\u003es_fs_info before running set() and clears fc-\u003es_fs_info\n--\nfs/smb/client/cifsfs.c-1053-\tfc-\u003esget_key = \u0026mnt_data;\nfs/smb/client/cifsfs.c:1054:\tsb = sget_fc(fc, cifs_match_super, set_anon_super_fc);\nfs/smb/client/cifsfs.c-1055-\tfc-\u003esget_key = NULL;\n--\nfs/super.c=337=static struct super_block *alloc_super(struct file_system_type *type, int flags,\n--\nfs/super.c-350-\t/*\nfs/super.c:351:\t * sget_fc() can have s_umount recursion.\nfs/super.c-352-\t *\n--\nfs/super.c=557=static void kill_super_notify(struct super_block *sb)\n--\nfs/super.c-564-\nfs/super.c:565:\t/* Drop sget_fc()'s claim; a never-registered entry stays with the sb. */\nfs/super.c-566-\tif (sb-\u003es_super_dev-\u003esd_dev) {\n--\nfs/super.c-572-\t * Let concurrent mounts know that this thing is really dead.\nfs/super.c:573:\t * sget_fc() skips SB_DEAD superblocks and calls test() under\nfs/super.c-574-\t * sb_lock, so set it under sb_lock: once we return no test()\n--\nfs/super.c=632=EXPORT_SYMBOL(deactivate_super);\n--\nfs/super.c-638- * Acquire a temporary reference on a superblock and try to trade it for\nfs/super.c:639: * an active reference. This is used in sget_fc() to wait for a\nfs/super.c-640- * superblock to either become SB_BORN or for it to pass through\n--\nfs/super.c=737=void generic_shutdown_super(struct super_block *sb)\n--\nfs/super.c-794-\t * superblock that it is dying. Every walker of @fs_supers outside\nfs/super.c:795:\t * of sget_fc() will now discard this superblock and treat it as\nfs/super.c-796-\t * dead.\nfs/super.c-797-\t *\nfs/super.c:798:\t * sget_fc() keeps finding the superblock until SB_DEAD is set, so\nfs/super.c-799-\t * a concurrent mounter waits until we passed sb-\u003ekill_sb().\n--\nfs/super.c=813=bool mount_capable(struct fs_context *fc)\n--\nfs/super.c-821-/**\nfs/super.c:822: * sget_fc - Find or create a superblock\nfs/super.c-823- * @fc:\tFilesystem context.\n--\nfs/super.c-852- */\nfs/super.c:853:struct super_block *sget_fc(struct fs_context *fc,\nfs/super.c-854-\t\t\t int (*test)(struct super_block *, struct fs_context *),\n--\nfs/super.c-934-}\nfs/super.c:935:EXPORT_SYMBOL(sget_fc);\nfs/super.c-936-\n--\nfs/super.c=1391=static int vfs_get_super(struct fs_context *fc,\n--\nfs/super.c-1398-\nfs/super.c:1399:\tsb = sget_fc(fc, test, set_anon_super_fc);\nfs/super.c-1400-\tif (IS_ERR(sb))\n--\nfs/super.c=1482=struct super_block *sget_dev(struct fs_context *fc, dev_t dev)\n--\nfs/super.c-1484-\tfc-\u003esget_key = \u0026dev;\nfs/super.c:1485:\treturn sget_fc(fc, super_s_dev_test, super_s_dev_set);\nfs/super.c-1486-}\n--\nfs/super.c=1798=int setup_bdev_super(struct super_block *sb, int sb_flags,\n--\nfs/super.c-1822-\nfs/super.c:1823:\t/* The sget_fc() entry is already published; pairs with bdev_freeze(). */\nfs/super.c-1824-\tsmp_mb();\n--\nfs/ubifs/super.c=2232=static int ubifs_get_tree(struct fs_context *fc)\n--\nfs/ubifs/super.c-2266-\nfs/ubifs/super.c:2267:\tsb = sget_fc(fc, sb_test, set_anon_super_fc);\nfs/ubifs/super.c-2268-\tif (IS_ERR(sb)) {\n"
} |
| 5/2 | 2026/09/09 21:12 | llm | patch-evaluator |
0mModel:gemini-3.7-flash Args: null Results: null Tokens: input: 8327 output: 33 thoughts: 59 Thoughts: **Analyzing the Filesystem Changes** Okay, time to dive in. I need to get a really granular understanding of these filesystem modifications. Let's start by scrutinizing the diff, paying close attention to the relevant sections. My focus is on the changes to `fs/super.c` and `fs/kernfs/mount.c` – that's where the core of this likely resides. I'll read through `fs/super.c` first, specifically lines 420-620 and then lines 860-940, to get a handle on what's going on within that file. I expect there to be the meat of the changes in this range. |
| 6/2 | 2026/09/09 21:12 | tool | read-file |
0mArgs:{
"File": "fs/super.c",
"FirstLine": 425,
"LineCount": 80
}Results: {
"Contents": " 425:\t}\n 426:\t\n 427:\t/* Superblock refcounting */\n 428:\t\n 429:\t/*\n 430:\t * Drop a superblock's passive reference. Must be called WITHOUT sb_lock held;\n 431:\t * put_super() acquires sb_lock itself when the final reference is dropped.\n 432:\t */\n 433:\tvoid put_super(struct super_block *s)\n 434:\t{\n 435:\t\tif (refcount_dec_and_test(\u0026s-\u003es_passive)) {\n 436:\t\t\tstruct file_system_type *type = s-\u003es_type;\n 437:\t\n 438:\t\t\tspin_lock(\u0026sb_lock);\n 439:\t\t\tlist_del_init(\u0026s-\u003es_list);\n 440:\t\t\thlist_del_init(\u0026s-\u003es_instances);\n 441:\t\t\tspin_unlock(\u0026sb_lock);\n 442:\t\n 443:\t\t\tWARN_ON(s-\u003es_dentry_lru.node);\n 444:\t\t\tWARN_ON(s-\u003es_inode_lru.node);\n 445:\t\t\tWARN_ON(s-\u003es_mounts);\n 446:\t\t\tcall_rcu(\u0026s-\u003ercu, destroy_super_rcu);\n 447:\t\t\t/* The unlink above may touch type-\u003efs_supers, so drop it last. */\n 448:\t\t\tput_filesystem(type);\n 449:\t\t}\n 450:\t}\n 451:\t\n 452:\tstruct super_dev {\n 453:\t\tdev_t\t\t\tsd_dev;\n 454:\t\tstruct super_block\t*sd_sb;\n 455:\t\trefcount_t\t\tsd_ref;\n 456:\t\tstruct rhlist_head\tsd_node;\n 457:\t\tstruct rcu_head\t\tsd_rcu;\n 458:\t};\n 459:\t\n 460:\tstatic struct rhltable super_dev_table;\n 461:\tstatic const struct rhashtable_params super_dev_params = {\n 462:\t\t.key_len\t= sizeof(dev_t),\n 463:\t\t.key_offset\t= offsetof(struct super_dev, sd_dev),\n 464:\t\t.head_offset\t= offsetof(struct super_dev, sd_node),\n 465:\t};\n 466:\t\n 467:\tstatic struct super_dev *super_dev_alloc(dev_t dev, struct super_block *sb)\n 468:\t{\n 469:\t\tstruct super_dev *fsd;\n 470:\t\n 471:\t\tfsd = kzalloc_obj(*fsd);\n 472:\t\tif (!fsd)\n 473:\t\t\treturn NULL;\n 474:\t\tfsd-\u003esd_dev = dev;\n 475:\t\tfsd-\u003esd_sb = sb;\n 476:\t\trefcount_set(\u0026fsd-\u003esd_ref, 1);\n 477:\t\treturn fsd;\n 478:\t}\n 479:\t\n 480:\tstatic void super_dev_put(struct super_dev *fsd)\n 481:\t{\n 482:\t\t/* Unlink only once unpinned, so a cursor never resumes from a removed node. */\n 483:\t\tif (fsd \u0026\u0026 refcount_dec_and_test(\u0026fsd-\u003esd_ref)) {\n 484:\t\t\trhltable_remove(\u0026super_dev_table, \u0026fsd-\u003esd_node, super_dev_params);\n 485:\t\t\tput_super(fsd-\u003esd_sb);\n 486:\t\t\tkfree_rcu(fsd, sd_rcu);\n 487:\t\t}\n 488:\t}\n 489:\t\n 490:\tvoid __init super_dev_init(void)\n 491:\t{\n 492:\t\tif (rhltable_init(\u0026super_dev_table, \u0026super_dev_params))\n 493:\t\t\tpanic(\"VFS: Cannot initialise super_dev_table\\n\");\n 494:\t}\n 495:\t\n 496:\tstatic int super_dev_insert(struct super_dev *fsd)\n 497:\t{\n 498:\t\tint err;\n 499:\t\n 500:\t\terr = rhltable_insert(\u0026super_dev_table, \u0026fsd-\u003esd_node, super_dev_params);\n 501:\t\tif (!err)\n 502:\t\t\trefcount_inc(\u0026fsd-\u003esd_sb-\u003es_passive);\n 503:\t\treturn err;\n 504:\t}\n"
} |
| 7/2 | 2026/09/09 21:12 | llm | patch-evaluator |
0mModel:gemini-3.7-flash Args: null Results: null Tokens: input: 9809 output: 33 thoughts: 32 Thoughts: Okay, here's my interpretation of those sections, tailored for someone who understands kernel code: **Analyzing `fs/super.c` Sections** Alright, time to dive into `fs/super.c`. Specifically, I'm focusing on lines 550 through 620 and then jumping ahead to lines 860 through 920. My initial thought is to quickly understand the core functionalities being discussed in those ranges. Given the file and these line numbers, I'm anticipating that I'll find code related to superblock operations. I'm expecting to get an overview of how the superblock is created and initialized, potentially covering aspects like reading it from disk, validating its contents, and any associated error handling. I'll be looking for clues regarding different filesystem types. I'll be paying close attention to any locking mechanisms employed, since `fs/super.c` is the core of how filesystems are mounted and managed. I need to be sure any locking is used correctly. I'll need to understand if the code deals with specific superblock operations, and if so, how these operations are defined and hooked into the generic VFS framework. Any interactions with underlying device drivers or block layer components will be critical. Furthermore, I'm anticipating potential discussions of filesystem-specific initialization routines or data structures, especially if those lines cover aspects like setting up the root inode or managing the free space on the filesystem. I'll keep an eye out for how this section handles superblock corruption or inconsistencies, and how they would be resolved or logged. I also might see an analysis of how metadata is handled and tracked. I'll also try to track how the file system's on-disk format is defined and utilized in this section. |
| 8/2 | 2026/09/09 21:12 | tool | read-file |
0mArgs:{
"File": "fs/super.c",
"FirstLine": 550,
"LineCount": 70
}Results: {
"Contents": " 550:\t\tsb_dev = super_dev_get(rcu_dereference_all(prev-\u003esd_node.next));\n 551:\t\trcu_read_unlock();\n 552:\t\n 553:\t\tsuper_dev_put(prev);\n 554:\t\treturn sb_dev;\n 555:\t}\n 556:\t\n 557:\tstatic void kill_super_notify(struct super_block *sb)\n 558:\t{\n 559:\t\tlockdep_assert_not_held(\u0026sb-\u003es_umount);\n 560:\t\n 561:\t\t/* already notified earlier */\n 562:\t\tif (sb-\u003es_flags \u0026 SB_DEAD)\n 563:\t\t\treturn;\n 564:\t\n 565:\t\t/* Drop sget_fc()'s claim; a never-registered entry stays with the sb. */\n 566:\t\tif (sb-\u003es_super_dev-\u003esd_dev) {\n 567:\t\t\tsuper_dev_put(sb-\u003es_super_dev);\n 568:\t\t\tsb-\u003es_super_dev = NULL;\n 569:\t\t}\n 570:\t\n 571:\t\t/*\n 572:\t\t * Let concurrent mounts know that this thing is really dead.\n 573:\t\t * sget_fc() skips SB_DEAD superblocks and calls test() under\n 574:\t\t * sb_lock, so set it under sb_lock: once we return no test()\n 575:\t\t * runs on this superblock anymore and none will start. Everyone\n 576:\t\t * else already saw SB_DYING and either discarded the superblock\n 577:\t\t * or waits for SB_DEAD.\n 578:\t\t */\n 579:\t\tspin_lock(\u0026sb_lock);\n 580:\t\tsuper_wake(sb, SB_DEAD);\n 581:\t\tspin_unlock(\u0026sb_lock);\n 582:\t}\n 583:\t\n 584:\t/**\n 585:\t *\tdeactivate_locked_super\t-\tdrop an active reference to superblock\n 586:\t *\t@s: superblock to deactivate\n 587:\t *\n 588:\t *\tDrops an active reference to superblock, converting it into a temporary\n 589:\t *\tone if there is no other active references left. In that case we\n 590:\t *\ttell fs driver to shut it down and drop the temporary reference we\n 591:\t *\thad just acquired.\n 592:\t *\n 593:\t *\tCaller holds exclusive lock on superblock; that lock is released.\n 594:\t */\n 595:\tvoid deactivate_locked_super(struct super_block *s)\n 596:\t{\n 597:\t\tstruct file_system_type *fs = s-\u003es_type;\n 598:\t\tif (atomic_dec_and_test(\u0026s-\u003es_active)) {\n 599:\t\t\tshrinker_free(s-\u003es_shrink);\n 600:\t\t\tfs-\u003ekill_sb(s);\n 601:\t\n 602:\t\t\tkill_super_notify(s);\n 603:\t\n 604:\t\t\t/* list_lru_destroy() may sleep; put_super() callers may not. */\n 605:\t\t\tlist_lru_destroy(\u0026s-\u003es_dentry_lru);\n 606:\t\t\tlist_lru_destroy(\u0026s-\u003es_inode_lru);\n 607:\t\n 608:\t\t\tput_super(s);\n 609:\t\t} else {\n 610:\t\t\tsuper_unlock_excl(s);\n 611:\t\t}\n 612:\t}\n 613:\t\n 614:\tEXPORT_SYMBOL(deactivate_locked_super);\n 615:\t\n 616:\t/**\n 617:\t *\tdeactivate_super\t-\tdrop an active reference to superblock\n 618:\t *\t@s: superblock to deactivate\n 619:\t *\n"
} |
| 9/2 | 2026/09/09 21:12 | llm | patch-evaluator |
0mModel:gemini-3.7-flash Args: null Results: null Tokens: input: 11287 output: 33 thoughts: 22 Thoughts: Okay, here's my interpretation of what's going through my mind as I approach that section of `fs/super.c`. **Diving into the Superblock Code** Alright, I'm focusing in on lines 860 to 935 of `fs/super.c`. This is likely where the core superblock handling is taking place. Given my expertise, I'm expecting to find key functions related to superblock initialization, mounting, unmounting, and possibly some management of the superblock's in-memory representation. I know this area intimately, so I'll be looking for nuances. I'm going to quickly scan for the main functions called. I'll be paying close attention to any error handling, and the structure definitions being used. I will be looking out for any potential race conditions. I'm going to be looking for how the superblock interacts with the underlying block device or storage. Any interesting locking mechanisms will be of particular interest, especially read-write locks or spinlocks used to protect the superblock data. I'm hoping to refresh my memory on the interactions of this code with the VFS layer, particularly how superblock information is communicated upwards. |
| 10/2 | 2026/09/09 21:12 | tool | read-file |
0mArgs:{
"File": "fs/super.c",
"FirstLine": 860,
"LineCount": 75
}Results: {
"Contents": " 860:\t\tint err;\n 861:\t\n 862:\t\t/*\n 863:\t\t * Never allow s_user_ns != \u0026init_user_ns when FS_USERNS_MOUNT or\n 864:\t\t * FS_USERNS_DELEGATABLE is not set, as the filesystem is likely\n 865:\t\t * unprepared to handle it. This can happen when fsconfig() is called\n 866:\t\t * from init_user_ns with an fs_fd opened in another user namespace.\n 867:\t\t */\n 868:\t\tif (user_ns != \u0026init_user_ns \u0026\u0026\n 869:\t\t !(fc-\u003efs_type-\u003efs_flags \u0026 (FS_USERNS_MOUNT | FS_USERNS_DELEGATABLE))) {\n 870:\t\t\terrorfc(fc, \"VFS: Mounting from non-initial user namespace is not allowed\");\n 871:\t\t\treturn ERR_PTR(-EPERM);\n 872:\t\t}\n 873:\t\n 874:\tretry:\n 875:\t\tspin_lock(\u0026sb_lock);\n 876:\t\tif (test) {\n 877:\t\t\thlist_for_each_entry(old, \u0026fc-\u003efs_type-\u003efs_supers, s_instances) {\n 878:\t\t\t\t/* Only unlinked at the last passive reference. */\n 879:\t\t\t\tif (super_flags(old, SB_DEAD))\n 880:\t\t\t\t\tcontinue;\n 881:\t\t\t\tif (test(old, fc))\n 882:\t\t\t\t\tgoto share_extant_sb;\n 883:\t\t\t}\n 884:\t\t}\n 885:\t\tif (!s) {\n 886:\t\t\tspin_unlock(\u0026sb_lock);\n 887:\t\n 888:\t\t\ts = alloc_super(fc-\u003efs_type, fc-\u003esb_flags, user_ns);\n 889:\t\t\tif (!s)\n 890:\t\t\t\treturn ERR_PTR(-ENOMEM);\n 891:\t\t\tgoto retry;\n 892:\t\t}\n 893:\t\n 894:\t\ts-\u003es_fs_info = fc-\u003es_fs_info;\n 895:\t\terr = set(s, fc);\n 896:\t\tif (err) {\n 897:\t\t\tVFS_WARN_ON_ONCE(s-\u003es_super_dev-\u003esd_dev);\n 898:\t\t\ts-\u003es_fs_info = NULL;\n 899:\t\t\tspin_unlock(\u0026sb_lock);\n 900:\t\t\tdestroy_unused_super(s);\n 901:\t\t\treturn ERR_PTR(err);\n 902:\t\t}\n 903:\t\tVFS_WARN_ON_ONCE(!s-\u003es_super_dev-\u003esd_dev);\n 904:\t\tfc-\u003es_fs_info = NULL;\n 905:\t\ts-\u003es_type = fc-\u003efs_type;\n 906:\t\ts-\u003es_iflags |= fc-\u003es_iflags;\n 907:\t\tstrscpy(s-\u003es_id, s-\u003es_type-\u003ename, sizeof(s-\u003es_id));\n 908:\t\t/*\n 909:\t\t * Make the superblock visible on @super_blocks and @fs_supers.\n 910:\t\t * It's in a nascent state and users should wait on SB_BORN or\n 911:\t\t * SB_DYING to be set.\n 912:\t\t */\n 913:\t\tlist_add_tail(\u0026s-\u003es_list, \u0026super_blocks);\n 914:\t\thlist_add_head(\u0026s-\u003es_instances, \u0026s-\u003es_type-\u003efs_supers);\n 915:\t\tspin_unlock(\u0026sb_lock);\n 916:\t\tget_filesystem(s-\u003es_type);\n 917:\t\tshrinker_register(s-\u003es_shrink);\n 918:\t\treturn s;\n 919:\t\n 920:\tshare_extant_sb:\n 921:\t\tif (user_ns != old-\u003es_user_ns || fc-\u003eexclusive) {\n 922:\t\t\tspin_unlock(\u0026sb_lock);\n 923:\t\t\tdestroy_unused_super(s);\n 924:\t\t\tif (fc-\u003eexclusive)\n 925:\t\t\t\twarnfc(fc, \"reusing existing filesystem not allowed\");\n 926:\t\t\telse\n 927:\t\t\t\twarnfc(fc, \"reusing existing filesystem in another namespace not allowed\");\n 928:\t\t\treturn ERR_PTR(-EBUSY);\n 929:\t\t}\n 930:\t\tif (!grab_super(old))\n 931:\t\t\tgoto retry;\n 932:\t\tdestroy_unused_super(s);\n 933:\t\treturn old;\n 934:\t}\n"
} |
| 11/2 | 2026/09/09 21:12 | llm | patch-evaluator |
0mModel:gemini-3.7-flash Args: null Results: null Tokens: input: 12816 output: 25 thoughts: 978 Thoughts: **Analyzing a Patch for Fuzzing Potential** Okay, so I need to understand this patch and assess its fuzzing potential. My first instinct is to dig into the commit history using `git log`, or at least check the commit context if a direct tool isn't available. Understanding the *why* behind this change is crucial. Alright, the patch modifies `fs/kernfs/mount.c` and `fs/super.c`. That's already interesting, especially the latter. Let's break down the `fs/super.c` changes: 1. **`put_super(struct super_block *s)`**: The original code placed `hlist_del_init(&sb->s_instances)` and `put_filesystem(type)` in `kill_super_notify()` and `deactivate_locked_super()`. Now, these are moved to `put_super()` under specific conditions related to passive reference counts. 2. **`kill_super_notify()`**: The removal of `hlist_del_init` from this function is noteworthy. It also looks like setting `SB_DEAD` now requires protection from `sb_lock` which is good. 3. **`sget_fc()`**: The changed conditional for `fs_supers` list traversal is also worth further investigation, as its related to finding dead superblocks. 4. **`kernfs_kill_sb()`**: A comment update here indicates a change in the superblock state to mark it dead. Essentially, it looks like this patch is refactoring how superblocks are managed and cleaned up, especially in concurrent scenarios. It's touching the lifecycle, locking, and list management of these superblocks. Now, the crucial question: **WorthFuzzing?** Definitely. `fs/super.c` is the core of the VFS superblock implementation. It's involved in superblock lifecycle, concurrent mounting, reference counting, locking, and list operations on critical data structures. This touches stuff like `sget_fc()`, `grab_super()`, `put_super()`, `kill_super_notify()`, `generic_shutdown_super()`, `deactivate_locked_super()` which I regularly use, so this looks like high-concurrency, critical VFS core logic. It's likely reachable through common syscalls like `mount`, `umount`, `fsopen`, `fsmount`, `fsconfig`, etc. Yes, this is core functionality and therefore is indeed worth fuzzing. Finally, regarding `EnableConfigs`: `fs/super.c` is always compiled. `fs/kernfs/mount.c` requires `CONFIG_KERNFS`. I'll need to double-check `fs/Makefile` and `fs/kernfs/Makefile` / `fs/Kconfig` to confirm any related kernel configurations. |
| 12/2 | 2026/09/09 21:13 | tool | grepper |
0mArgs:{
"Expression": "kernfs",
"PathPrefix": "fs/Makefile"
}Results: {
"Output": "fs/Makefile=55=obj-$(CONFIG_PROC_FS)\t\t+= proc/\nfs/Makefile:56:obj-$(CONFIG_KERNFS)\t\t+= kernfs/\nfs/Makefile-57-obj-$(CONFIG_SYSFS)\t\t+= sysfs/\n"
} |
| 13/2 | 2026/09/09 21:13 | llm | patch-evaluator |
0mModel:gemini-3.7-flash Args: null Results: null Tokens: input: 14506 output: 26 thoughts: 20 Thoughts: Here's my take on those thoughts: **Navigating the Kernel Configuration Landscape** Okay, so I need to figure out where the configuration options related to whatever filesystem-related task I'm working on are defined. My first instinct, given my experience, is to zero in on `fs/kernfs/Kconfig` or, more broadly, `fs/Kconfig`. These are the likely candidates for containing the relevant Kconfig files. They're central to how we manage and expose filesystem-specific parameters to the user during the kernel build process. I'll start with those and see what I find. |
| 14/2 | 2026/09/09 21:13 | tool | grepper |
0mArgs:{
"Expression": "config KERNFS",
"PathPrefix": "fs/"
}Results: {
"Output": "fs/kernfs/Kconfig-5-\nfs/kernfs/Kconfig:6:config KERNFS\nfs/kernfs/Kconfig-7-\tbool\n"
} |
| 15/2 | 2026/09/09 21:13 | llm | patch-evaluator |
0mModel:gemini-3.7-flash Args: null Results: null Tokens: input: 14731 output: 25 thoughts: 524 Thoughts: **Analyzing Filesystem Superblock Handling** Okay, so KERNFS is a boolean config option, selected by the likes of SYSFS and CGROUPS, but `fs/super.c` is always compiled in – it's unconditional. My initial thought is to figure out if there are any specific configurations I need to consider, but it seems like `fs/super.c` is core VFS, always included in `vmlinux`. I need to nail down the `FocusSymbols` for this analysis. I have to avoid the usual suspects – the ubiquitous functions and hot paths that are called by practically everything. Instead, I'm looking for the functions that *specifically* implement the changed logic or act as API entry points for this particular subsystem. Looking at the patch, I see these modified functions: 1. `sget_fc`: It's supposed to find or create a superblock using `fs_context`, and the logic seems to skip dead superblocks. 2. `kill_super_notify`: This is a notification function for superblock teardown. It's modified with `super_wake(sb, SB_DEAD)`. It's static, so I need to make sure it's not inlined. 3. `put_super`: A non-static function in `fs/super.c`. It's declared somewhere in `include/linux/fs.h` or `fs/internal.h`, so I'll double-check that. 4. `deactivate_locked_super`: Another non-static exported function in `fs/super.c`. 5. `generic_shutdown_super`: Also a non-static exported function in `fs/super.c`. This is part of the shutdown path. 6. `kernfs_kill_sb`: Non-static, but in `fs/kernfs/mount.c`. Now, I'll need to scrutinize the callers and declarations of these symbols to confirm which are valid, non-ubiquitous symbols within the vmlinux kernel. |
| 16/2 | 2026/09/09 21:13 | tool | grepper |
0mArgs:{
"Expression": "put_super",
"PathPrefix": "fs/"
}Results: {
"Output": "\nFull output is too long, showing 500 out of 623 lines.\nUse more precise expression if possible.\n\nfs/adfs/super.c=54=static int adfs_checkdiscrecord(struct adfs_discrecord *dr)\n--\nfs/adfs/super.c-92-\nfs/adfs/super.c:93:static void adfs_put_super(struct super_block *sb)\nfs/adfs/super.c-94-{\n--\nfs/adfs/super.c=244=static const struct super_operations adfs_sops = {\n--\nfs/adfs/super.c-248-\t.write_inode\t= adfs_write_inode,\nfs/adfs/super.c:249:\t.put_super\t= adfs_put_super,\nfs/adfs/super.c-250-\t.statfs\t\t= adfs_statfs,\n--\nfs/affs/super.c=49=static void\nfs/affs/super.c:50:affs_put_super(struct super_block *sb)\nfs/affs/super.c-51-{\n--\nfs/affs/super.c=150=static const struct super_operations affs_sops = {\n--\nfs/affs/super.c-154-\t.evict_inode\t= affs_evict_inode,\nfs/affs/super.c:155:\t.put_super\t= affs_put_super,\nfs/affs/super.c-156-\t.sync_fs\t= affs_sync_fs,\n--\nfs/befs/ChangeLog=176=Version 0.45 (2001-10-29)\n--\nfs/befs/ChangeLog-183-\tstructures into the generic pointer fields of the public structures \nfs/befs/ChangeLog:184:\twith kmalloc(). put_super and put_inode free them. This allows us not \nfs/befs/ChangeLog-185-\tto have to touch the definitions of the public structures in \n--\nfs/befs/linuxvfs.c=56=static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,\nfs/befs/linuxvfs.c-57-\t\t\tchar **out, int *out_len);\nfs/befs/linuxvfs.c:58:static void befs_put_super(struct super_block *);\nfs/befs/linuxvfs.c-59-static int befs_statfs(struct dentry *, struct kstatfs *);\n--\nfs/befs/linuxvfs.c=68=static const struct super_operations befs_sops = {\n--\nfs/befs/linuxvfs.c-70-\t.free_inode\t= befs_free_inode, /* deallocate an inode */\nfs/befs/linuxvfs.c:71:\t.put_super\t= befs_put_super,\t/* uninit super */\nfs/befs/linuxvfs.c-72-\t.statfs\t\t= befs_statfs,\t/* statfs */\n--\nfs/befs/linuxvfs.c=748=static void\nfs/befs/linuxvfs.c:749:befs_put_super(struct super_block *sb)\nfs/befs/linuxvfs.c-750-{\n--\nfs/bfs/inode.c=195=static void bfs_evict_inode(struct inode *inode)\n--\nfs/bfs/inode.c-242-\nfs/bfs/inode.c:243:static void bfs_put_super(struct super_block *s)\nfs/bfs/inode.c-244-{\n--\nfs/bfs/inode.c=318=static const struct super_operations bfs_sops = {\n--\nfs/bfs/inode.c-323-\t.evict_inode\t= bfs_evict_inode,\nfs/bfs/inode.c:324:\t.put_super\t= bfs_put_super,\nfs/bfs/inode.c-325-\t.statfs\t\t= bfs_statfs,\n--\nfs/btrfs/super.c=69=static struct file_system_type btrfs_fs_type;\nfs/btrfs/super.c-70-\nfs/btrfs/super.c:71:static void btrfs_put_super(struct super_block *sb)\nfs/btrfs/super.c-72-{\n--\nfs/btrfs/super.c=2526=static const struct super_operations btrfs_super_ops = {\n--\nfs/btrfs/super.c-2528-\t.evict_inode\t= btrfs_evict_inode,\nfs/btrfs/super.c:2529:\t.put_super\t= btrfs_put_super,\nfs/btrfs/super.c-2530-\t.sync_fs\t= btrfs_sync_fs,\n--\nfs/ceph/super.c=38=static LIST_HEAD(ceph_fsc_list);\n--\nfs/ceph/super.c-48- */\nfs/ceph/super.c:49:static void ceph_put_super(struct super_block *s)\nfs/ceph/super.c-50-{\n--\nfs/ceph/super.c=1048=static const struct super_operations ceph_super_ops = {\n--\nfs/ceph/super.c-1054-\t.sync_fs = ceph_sync_fs,\nfs/ceph/super.c:1055:\t.put_super\t= ceph_put_super,\nfs/ceph/super.c-1056-\t.show_options = ceph_show_options,\n--\nfs/coda/inode.c=39=static void coda_evict_inode(struct inode *);\nfs/coda/inode.c:40:static void coda_put_super(struct super_block *);\nfs/coda/inode.c-41-static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);\n--\nfs/coda/inode.c=100=static const struct super_operations coda_super_operations =\n--\nfs/coda/inode.c-104-\t.evict_inode\t= coda_evict_inode,\nfs/coda/inode.c:105:\t.put_super\t= coda_put_super,\nfs/coda/inode.c-106-\t.statfs\t\t= coda_statfs,\n--\nfs/coda/inode.c=199=static int coda_fill_super(struct super_block *sb, struct fs_context *fc)\n--\nfs/coda/inode.c-277-\nfs/coda/inode.c:278:static void coda_put_super(struct super_block *sb)\nfs/coda/inode.c-279-{\n--\nfs/erofs/super.c=946=static void erofs_kill_sb(struct super_block *sb)\n--\nfs/erofs/super.c-959-\nfs/erofs/super.c:960:static void erofs_put_super(struct super_block *sb)\nfs/erofs/super.c-961-{\n--\nfs/erofs/super.c=1132=const struct super_operations erofs_sops = {\nfs/erofs/super.c:1133:\t.put_super = erofs_put_super,\nfs/erofs/super.c-1134-\t.alloc_inode = erofs_alloc_inode,\n--\nfs/exfat/super.c=34=static void exfat_set_iocharset(struct exfat_mount_options *opts,\n--\nfs/exfat/super.c-43-\nfs/exfat/super.c:44:static void exfat_put_super(struct super_block *sb)\nfs/exfat/super.c-45-{\n--\nfs/exfat/super.c=206=static const struct super_operations exfat_sops = {\n--\nfs/exfat/super.c-210-\t.evict_inode\t= exfat_evict_inode,\nfs/exfat/super.c:211:\t.put_super\t= exfat_put_super,\nfs/exfat/super.c-212-\t.statfs\t\t= exfat_statfs,\n--\nfs/ext2/super.c=165=static inline void ext2_quota_off_umount(struct super_block *sb)\n--\nfs/ext2/super.c-169-\nfs/ext2/super.c:170:static void ext2_put_super (struct super_block * sb)\nfs/ext2/super.c-171-{\n--\nfs/ext2/super.c=361=static const struct super_operations ext2_sops = {\n--\nfs/ext2/super.c-366-\t.evict_inode\t= ext2_evict_inode,\nfs/ext2/super.c:367:\t.put_super\t= ext2_put_super,\nfs/ext2/super.c-368-\t.sync_fs\t= ext2_sync_fs,\n--\nfs/ext4/super.c=1269=static void ext4_flex_groups_free(struct ext4_sb_info *sbi)\n--\nfs/ext4/super.c-1281-\nfs/ext4/super.c:1282:static void ext4_put_super(struct super_block *sb)\nfs/ext4/super.c-1283-{\n--\nfs/ext4/super.c=1677=static const struct super_operations ext4_sops = {\n--\nfs/ext4/super.c-1685-\t.evict_inode\t= ext4_evict_inode,\nfs/ext4/super.c:1686:\t.put_super\t= ext4_put_super,\nfs/ext4/super.c-1687-\t.sync_fs\t= ext4_sync_fs,\n--\nfs/f2fs/f2fs.h=511=struct discard_policy {\n--\nfs/f2fs/f2fs.h-520-\tbool ordered;\t\t\t/* issue discard by lba order */\nfs/f2fs/f2fs.h:521:\tbool timeout;\t\t\t/* discard timeout for put_super */\nfs/f2fs/f2fs.h-522-\tunsigned int granularity;\t/* discard granularity */\n--\nfs/f2fs/shrinker.c=40=unsigned long f2fs_shrink_count(struct shrinker *shrink,\n--\nfs/f2fs/shrinker.c-51-\nfs/f2fs/shrinker.c:52:\t\t/* stop f2fs_put_super */\nfs/f2fs/shrinker.c-53-\t\tif (!mutex_trylock(\u0026sbi-\u003eumount_mutex)) {\n--\nfs/f2fs/shrinker.c=79=unsigned long f2fs_shrink_scan(struct shrinker *shrink,\n--\nfs/f2fs/shrinker.c-98-\nfs/f2fs/shrinker.c:99:\t\t/* stop f2fs_put_super */\nfs/f2fs/shrinker.c-100-\t\tif (!mutex_trylock(\u0026sbi-\u003eumount_mutex)) {\n--\nfs/f2fs/shrinker.c=134=unsigned int f2fs_donate_files(void)\n--\nfs/f2fs/shrinker.c-144-\nfs/f2fs/shrinker.c:145:\t\t/* stop f2fs_put_super */\nfs/f2fs/shrinker.c-146-\t\tif (!mutex_trylock(\u0026sbi-\u003eumount_mutex)) {\n--\nfs/f2fs/shrinker.c=205=void f2fs_reclaim_caches(unsigned int reclaim_caches_kb)\n--\nfs/f2fs/shrinker.c-214-\nfs/f2fs/shrinker.c:215:\t\t/* stop f2fs_put_super */\nfs/f2fs/shrinker.c-216-\t\tif (!mutex_trylock(\u0026sbi-\u003eumount_mutex)) {\n--\nfs/f2fs/super.c=1996=static void destroy_device_list(struct f2fs_sb_info *sbi)\n--\nfs/f2fs/super.c-2009-\nfs/f2fs/super.c:2010:static void f2fs_put_super(struct super_block *sb)\nfs/f2fs/super.c-2011-{\n--\nfs/f2fs/super.c=3591=void f2fs_quota_off_umount(struct super_block *sb)\n--\nfs/f2fs/super.c-3608-\t * This can cause NULL exception for node_inode in end_io, since\nfs/f2fs/super.c:3609:\t * put_super already dropped it.\nfs/f2fs/super.c-3610-\t */\n--\nfs/f2fs/super.c=3730=static const struct super_operations f2fs_sops = {\n--\nfs/f2fs/super.c-3742-\t.evict_inode\t= f2fs_evict_inode,\nfs/f2fs/super.c:3743:\t.put_super\t= f2fs_put_super,\nfs/f2fs/super.c-3744-\t.sync_fs\t= f2fs_sync_fs,\n--\nfs/fat/inode.c=761=static void delayed_free(struct rcu_head *p)\n--\nfs/fat/inode.c-769-\nfs/fat/inode.c:770:static void fat_put_super(struct super_block *sb)\nfs/fat/inode.c-771-{\n--\nfs/fat/inode.c=969=static const struct super_operations fat_sops = {\n--\nfs/fat/inode.c-974-\t.evict_inode\t= fat_evict_inode,\nfs/fat/inode.c:975:\t.put_super\t= fat_put_super,\nfs/fat/inode.c-976-\t.statfs\t\t= fat_statfs,\n--\nfs/gfs2/super.c=539=void gfs2_make_fs_ro(struct gfs2_sbd *sdp)\n--\nfs/gfs2/super.c-571-/**\nfs/gfs2/super.c:572: * gfs2_put_super - Unmount the filesystem\nfs/gfs2/super.c-573- * @sb: The VFS superblock\n--\nfs/gfs2/super.c-576-\nfs/gfs2/super.c:577:static void gfs2_put_super(struct super_block *sb)\nfs/gfs2/super.c-578-{\n--\nfs/gfs2/super.c=1569=const struct super_operations gfs2_super_ops = {\n--\nfs/gfs2/super.c-1574-\t.evict_inode\t\t= gfs2_evict_inode,\nfs/gfs2/super.c:1575:\t.put_super\t\t= gfs2_put_super,\nfs/gfs2/super.c-1576-\t.sync_fs\t\t= gfs2_sync_fs,\n--\nfs/hfs/super.c=35=static int hfs_sync_fs(struct super_block *sb, int wait)\n--\nfs/hfs/super.c-47-/*\nfs/hfs/super.c:48: * hfs_put_super()\nfs/hfs/super.c-49- *\nfs/hfs/super.c:50: * This is the put_super() entry in the super_operations structure for\nfs/hfs/super.c-51- * HFS filesystems. The purpose is to release the resources\n--\nfs/hfs/super.c-53- */\nfs/hfs/super.c:54:static void hfs_put_super(struct super_block *sb)\nfs/hfs/super.c-55-{\n--\nfs/hfs/super.c=188=static const struct super_operations hfs_super_operations = {\n--\nfs/hfs/super.c-192-\t.evict_inode\t= hfs_evict_inode,\nfs/hfs/super.c:193:\t.put_super\t= hfs_put_super,\nfs/hfs/super.c-194-\t.sync_fs\t= hfs_sync_fs,\n--\nfs/hfsplus/super.c=321=static void delayed_free(struct rcu_head *p)\n--\nfs/hfsplus/super.c-328-\nfs/hfsplus/super.c:329:static void hfsplus_put_super(struct super_block *sb)\nfs/hfsplus/super.c-330-{\n--\nfs/hfsplus/super.c=408=static const struct super_operations hfsplus_sops = {\n--\nfs/hfsplus/super.c-412-\t.evict_inode\t= hfsplus_evict_inode,\nfs/hfsplus/super.c:413:\t.put_super\t= hfsplus_put_super,\nfs/hfsplus/super.c-414-\t.sync_fs\t= hfsplus_sync_fs,\n--\nfs/hpfs/super.c=122=static void lazy_free_sbi(struct rcu_head *rcu)\n--\nfs/hpfs/super.c-126-\nfs/hpfs/super.c:127:static void hpfs_put_super(struct super_block *s)\nfs/hpfs/super.c-128-{\n--\nfs/hpfs/super.c=491=static const struct super_operations hpfs_sops =\n--\nfs/hpfs/super.c-495-\t.evict_inode\t= hpfs_evict_inode,\nfs/hpfs/super.c:496:\t.put_super\t= hpfs_put_super,\nfs/hpfs/super.c-497-\t.statfs\t\t= hpfs_statfs,\n--\nfs/hugetlbfs/inode.c=1094=static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)\n--\nfs/hugetlbfs/inode.c-1124-\nfs/hugetlbfs/inode.c:1125:static void hugetlbfs_put_super(struct super_block *sb)\nfs/hugetlbfs/inode.c-1126-{\n--\nfs/hugetlbfs/inode.c=1235=static const struct super_operations hugetlbfs_ops = {\n--\nfs/hugetlbfs/inode.c-1240-\t.statfs\t\t= hugetlbfs_statfs,\nfs/hugetlbfs/inode.c:1241:\t.put_super\t= hugetlbfs_put_super,\nfs/hugetlbfs/inode.c-1242-\t.show_options\t= hugetlbfs_show_options,\n--\nfs/internal.h=138=struct super_block *user_get_super(dev_t, bool excl);\nfs/internal.h:139:void put_super(struct super_block *sb);\nfs/internal.h-140-void __init super_dev_init(void);\n--\nfs/isofs/inode.c=48=static int isofs_dentry_cmp_ms(const struct dentry *dentry,\n--\nfs/isofs/inode.c-51-\nfs/isofs/inode.c:52:static void isofs_put_super(struct super_block *sb)\nfs/isofs/inode.c-53-{\n--\nfs/isofs/inode.c=122=static const struct super_operations isofs_sops = {\n--\nfs/isofs/inode.c-124-\t.free_inode\t= isofs_free_inode,\nfs/isofs/inode.c:125:\t.put_super\t= isofs_put_super,\nfs/isofs/inode.c-126-\t.statfs\t\t= isofs_statfs,\n--\nfs/jffs2/super.c-33-\nfs/jffs2/super.c:34:static void jffs2_put_super(struct super_block *);\nfs/jffs2/super.c-35-\n--\nfs/jffs2/super.c=244=static const struct super_operations jffs2_super_operations =\n--\nfs/jffs2/super.c-247-\t.free_inode =\tjffs2_free_inode,\nfs/jffs2/super.c:248:\t.put_super =\tjffs2_put_super,\nfs/jffs2/super.c-249-\t.statfs =\tjffs2_statfs,\n--\nfs/jffs2/super.c=310=static int jffs2_init_fs_context(struct fs_context *fc)\n--\nfs/jffs2/super.c-322-\nfs/jffs2/super.c:323:static void jffs2_put_super (struct super_block *sb)\nfs/jffs2/super.c-324-{\n--\nfs/jfs/super.c=180=static inline void jfs_quota_off_umount(struct super_block *sb)\n--\nfs/jfs/super.c-184-\nfs/jfs/super.c:185:static void jfs_put_super(struct super_block *sb)\nfs/jfs/super.c-186-{\n--\nfs/jfs/super.c-189-\nfs/jfs/super.c:190:\tjfs_info(\"In jfs_put_super\");\nfs/jfs/super.c-191-\n--\nfs/jfs/super.c=844=static const struct super_operations jfs_super_operations = {\n--\nfs/jfs/super.c-849-\t.evict_inode\t= jfs_evict_inode,\nfs/jfs/super.c:850:\t.put_super\t= jfs_put_super,\nfs/jfs/super.c-851-\t.sync_fs\t= jfs_sync_fs,\n--\nfs/minix/inode.c=47=static void minix_evict_inode(struct inode *inode)\n--\nfs/minix/inode.c-61-\nfs/minix/inode.c:62:static void minix_put_super(struct super_block *sb)\nfs/minix/inode.c-63-{\n--\nfs/minix/inode.c=129=static const struct super_operations minix_sops = {\n--\nfs/minix/inode.c-134-\t.evict_inode\t= minix_evict_inode,\nfs/minix/inode.c:135:\t.put_super\t= minix_put_super,\nfs/minix/inode.c-136-\t.statfs\t\t= minix_statfs,\n--\nfs/nilfs2/super.c=430=int nilfs_resize_fs(struct super_block *sb, __u64 newsize)\n--\nfs/nilfs2/super.c-504-\nfs/nilfs2/super.c:505:static void nilfs_put_super(struct super_block *sb)\nfs/nilfs2/super.c-506-{\n--\nfs/nilfs2/super.c=705=static const struct super_operations nilfs_sops = {\n--\nfs/nilfs2/super.c-709-\t.evict_inode = nilfs_evict_inode,\nfs/nilfs2/super.c:710:\t.put_super = nilfs_put_super,\nfs/nilfs2/super.c-711-\t.sync_fs = nilfs_sync_fs,\n--\nfs/ntfs/super.c=1668=static void ntfs_volume_free(struct ntfs_volume *vol)\n--\nfs/ntfs/super.c-1707-/*\nfs/ntfs/super.c:1708: * ntfs_put_super - called by the vfs to unmount a volume\nfs/ntfs/super.c-1709- * @sb:\t\tvfs superblock of volume to unmount\nfs/ntfs/super.c-1710- */\nfs/ntfs/super.c:1711:static void ntfs_put_super(struct super_block *sb)\nfs/ntfs/super.c-1712-{\n--\nfs/ntfs/super.c=2160=static const struct super_operations ntfs_sops = {\n--\nfs/ntfs/super.c-2164-\t.write_inode\t= ntfs_write_inode,\t/* VFS: Write dirty inode to disk. */\nfs/ntfs/super.c:2165:\t.put_super\t= ntfs_put_super,\t/* Syscall: umount. */\nfs/ntfs/super.c-2166-\t.shutdown\t= ntfs_shutdown,\n--\nfs/ntfs3/super.c=709=static void ntfs3_free_sbi(struct ntfs_sb_info *sbi)\n--\nfs/ntfs3/super.c-721-\nfs/ntfs3/super.c:722:static void ntfs_put_super(struct super_block *sb)\nfs/ntfs3/super.c-723-{\n--\nfs/ntfs3/super.c=870=static const struct super_operations ntfs_sops = {\n--\nfs/ntfs3/super.c-873-\t.evict_inode = ntfs_evict_inode,\nfs/ntfs3/super.c:874:\t.put_super = ntfs_put_super,\nfs/ntfs3/super.c-875-\t.statfs = ntfs_statfs,\n--\nfs/ocfs2/ocfs2_trace.h=1673=TRACE_EVENT(ocfs2_parse_options,\n--\nfs/ocfs2/ocfs2_trace.h-1686-\nfs/ocfs2/ocfs2_trace.h:1687:DEFINE_OCFS2_POINTER_EVENT(ocfs2_put_super);\nfs/ocfs2/ocfs2_trace.h-1688-\n--\nfs/ocfs2/super.c=89=static int ocfs2_show_options(struct seq_file *s, struct dentry *root);\nfs/ocfs2/super.c:90:static void ocfs2_put_super(struct super_block *sb);\nfs/ocfs2/super.c-91-static int ocfs2_mount_volume(struct super_block *sb);\n--\nfs/ocfs2/super.c=128=static const struct super_operations ocfs2_sops = {\n--\nfs/ocfs2/super.c-134-\t.sync_fs\t= ocfs2_sync_fs,\nfs/ocfs2/super.c:135:\t.put_super\t= ocfs2_put_super,\nfs/ocfs2/super.c-136-\t.show_options = ocfs2_show_options,\n--\nfs/ocfs2/super.c=1534=static void __exit ocfs2_exit(void)\n--\nfs/ocfs2/super.c-1546-\nfs/ocfs2/super.c:1547:static void ocfs2_put_super(struct super_block *sb)\nfs/ocfs2/super.c-1548-{\nfs/ocfs2/super.c:1549:\ttrace_ocfs2_put_super(sb);\nfs/ocfs2/super.c-1550-\n--\nfs/omfs/inode.c=204=struct inode *omfs_iget(struct super_block *sb, ino_t ino)\n--\nfs/omfs/inode.c-264-\nfs/omfs/inode.c:265:static void omfs_put_super(struct super_block *sb)\nfs/omfs/inode.c-266-{\n--\nfs/omfs/inode.c=320=static const struct super_operations omfs_sops = {\n--\nfs/omfs/inode.c-322-\t.evict_inode\t= omfs_evict_inode,\nfs/omfs/inode.c:323:\t.put_super\t= omfs_put_super,\nfs/omfs/inode.c-324-\t.statfs\t\t= omfs_statfs,\n--\nfs/overlayfs/super.c=213=static void ovl_destroy_inode(struct inode *inode)\n--\nfs/overlayfs/super.c-224-\nfs/overlayfs/super.c:225:static void ovl_put_super(struct super_block *sb)\nfs/overlayfs/super.c-226-{\n--\nfs/overlayfs/super.c=297=static const struct super_operations ovl_super_operations = {\n--\nfs/overlayfs/super.c-301-\t.drop_inode\t= inode_just_drop,\nfs/overlayfs/super.c:302:\t.put_super\t= ovl_put_super,\nfs/overlayfs/super.c-303-\t.sync_fs\t= ovl_sync_fs,\n--\nfs/qnx6/inode.c=29=static const struct super_operations qnx6_sops;\nfs/qnx6/inode.c-30-\nfs/qnx6/inode.c:31:static void qnx6_put_super(struct super_block *sb);\nfs/qnx6/inode.c-32-static struct inode *qnx6_alloc_inode(struct super_block *sb);\n--\nfs/qnx6/inode.c=38=static const struct super_operations qnx6_sops = {\n--\nfs/qnx6/inode.c-40-\t.free_inode\t= qnx6_free_inode,\nfs/qnx6/inode.c:41:\t.put_super\t= qnx6_put_super,\nfs/qnx6/inode.c-42-\t.statfs\t\t= qnx6_statfs,\n--\nfs/qnx6/inode.c=291=static int qnx6_fill_super(struct super_block *s, struct fs_context *fc)\n--\nfs/qnx6/inode.c-473-\nfs/qnx6/inode.c:474:static void qnx6_put_super(struct super_block *sb)\nfs/qnx6/inode.c-475-{\n--\nfs/quota/quota.c=866=static struct super_block *quotactl_block(const char __user *special, int cmd)\n--\nfs/quota/quota.c-899-\t\tsb_end_write(sb);\nfs/quota/quota.c:900:\t\tput_super(sb);\nfs/quota/quota.c-901-\t\tcond_resched();\n--\nfs/smb/client/misc.c=899=static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *),\n--\nfs/smb/client/misc.c-925-\nfs/smb/client/misc.c:926:static void __cifs_put_super(struct super_block *sb)\nfs/smb/client/misc.c-927-{\n--\nfs/smb/client/misc.c=943=void cifs_put_tcp_super(struct super_block *sb)\nfs/smb/client/misc.c-944-{\nfs/smb/client/misc.c:945:\t__cifs_put_super(sb);\nfs/smb/client/misc.c-946-}\n--\nfs/squashfs/super.c=571=static int squashfs_statfs(struct dentry *dentry, struct kstatfs *buf)\n--\nfs/squashfs/super.c-590-\nfs/squashfs/super.c:591:static void squashfs_put_super(struct super_block *sb)\nfs/squashfs/super.c-592-{\n--\nfs/squashfs/super.c=694=static const struct super_operations squashfs_super_ops = {\n--\nfs/squashfs/super.c-697-\t.statfs = squashfs_statfs,\nfs/squashfs/super.c:698:\t.put_super = squashfs_put_super,\nfs/squashfs/super.c-699-\t.show_options = squashfs_show_options,\n--\nfs/super.c=337=static struct super_block *alloc_super(struct file_system_type *type, int flags,\n--\nfs/super.c-430- * Drop a superblock's passive reference. Must be called WITHOUT sb_lock held;\nfs/super.c:431: * put_super() acquires sb_lock itself when the final reference is dropped.\nfs/super.c-432- */\nfs/super.c:433:void put_super(struct super_block *s)\nfs/super.c-434-{\n--\nfs/super.c=480=static void super_dev_put(struct super_dev *fsd)\n--\nfs/super.c-484-\t\trhltable_remove(\u0026super_dev_table, \u0026fsd-\u003esd_node, super_dev_params);\nfs/super.c:485:\t\tput_super(fsd-\u003esd_sb);\nfs/super.c-486-\t\tkfree_rcu(fsd, sd_rcu);\n--\nfs/super.c=595=void deactivate_locked_super(struct super_block *s)\n--\nfs/super.c-603-\nfs/super.c:604:\t\t/* list_lru_destroy() may sleep; put_super() callers may not. */\nfs/super.c-605-\t\tlist_lru_destroy(\u0026s-\u003es_dentry_lru);\n--\nfs/super.c-607-\nfs/super.c:608:\t\tput_super(s);\nfs/super.c-609-\t} else {\n--\nfs/super.c=646=static bool grab_super(struct super_block *sb)\n--\nfs/super.c-654-\t\tif (atomic_inc_not_zero(\u0026sb-\u003es_active)) {\nfs/super.c:655:\t\t\tput_super(sb);\nfs/super.c-656-\t\t\treturn true;\n--\nfs/super.c-660-\twait_var_event(\u0026sb-\u003es_flags, super_flags(sb, SB_DEAD));\nfs/super.c:661:\tput_super(sb);\nfs/super.c-662-\treturn false;\n--\nfs/super.c=737=void generic_shutdown_super(struct super_block *sb)\n--\nfs/super.c-763-\n\n"
} |
| 17/2 | 2026/09/09 21:13 | llm | patch-evaluator |
0mModel:gemini-3.7-flash Args: null Results: null Tokens: input: 24855 output: 27 thoughts: 145 Thoughts: **My Initial Assessment of the Shutdown Sequence** Okay, so I'm looking at a kernel shutdown sequence, specifically focusing on how superblocks are handled. I see a chain of functions involved: `sget_fc`, `put_super`, `deactivate_locked_super`, `kill_super_notify`, `generic_shutdown_super`, and `kernfs_kill_sb`. My immediate instinct is to dissect this step by step. I'm especially curious about `kill_super_notify`. I vaguely recall its purpose and I want to confirm if my memory is correct. First things first, I'll quickly verify if `kill_super_notify` is indeed declared as `static`. Yes, confirmed: `static void kill_super_notify(struct super_block *sb)` within `fs/super.c`. Perfect, that reinforces my initial understanding. Now, I need to know the call sites. Where is this function actually invoked within this shutdown process? Is it just called by `deactivate_locked_super(s)` or other superblock cleaning routines like `kill_anon_super(sb)`, or are there other parts of the system that rely on it? To be sure, I'll need to run a broad search for `kill_super_notify` throughout the entire codebase. This will give me the complete picture of its usage and interactions. This context will be crucial to understanding the overall superblock teardown. |
| 18/2 | 2026/09/09 21:13 | tool | grepper |
0mArgs:{
"Expression": "kill_super_notify",
"PathPrefix": "fs/"
}Results: {
"Output": "fs/super.c=545=static struct super_dev *super_dev_next(struct super_dev *prev)\n--\nfs/super.c-556-\nfs/super.c:557:static void kill_super_notify(struct super_block *sb)\nfs/super.c-558-{\n--\nfs/super.c=595=void deactivate_locked_super(struct super_block *s)\n--\nfs/super.c-601-\nfs/super.c:602:\t\tkill_super_notify(s);\nfs/super.c-603-\n--\nfs/super.c=1366=void kill_anon_super(struct super_block *sb)\n--\nfs/super.c-1369-\tgeneric_shutdown_super(sb);\nfs/super.c:1370:\tkill_super_notify(sb);\nfs/super.c-1371-\tfree_anon_bdev(dev);\n"
} |
| 19/2 | 2026/09/09 21:13 | llm | patch-evaluator |
0mModel:gemini-3.7-flash Args: null Results: null Tokens: input: 25584 output: 19 thoughts: 20 Thoughts: Here's my thought process, as it stands: **Digging Deeper for Impact** Okay, so we're looking at `kill_super_notify`. My initial focus was likely on a specific area, but I'm thinking we should broaden the scope of our search. Just to be thorough and ensure we don't miss any potential interactions or dependencies, I'm going to run a full-tree search for `kill_super_notify`. This will let me see if it's referenced anywhere unexpected, and help me understand the broader impact of this function across the codebase, not just in the immediate area I started investigating. Better to cast a wide net here. |
| 20/2 | 2026/09/09 21:13 | tool | grepper |
0mArgs:{
"Expression": "kill_super_notify"
}Results: {
"Output": "fs/super.c=545=static struct super_dev *super_dev_next(struct super_dev *prev)\n--\nfs/super.c-556-\nfs/super.c:557:static void kill_super_notify(struct super_block *sb)\nfs/super.c-558-{\n--\nfs/super.c=595=void deactivate_locked_super(struct super_block *s)\n--\nfs/super.c-601-\nfs/super.c:602:\t\tkill_super_notify(s);\nfs/super.c-603-\n--\nfs/super.c=1366=void kill_anon_super(struct super_block *sb)\n--\nfs/super.c-1369-\tgeneric_shutdown_super(sb);\nfs/super.c:1370:\tkill_super_notify(sb);\nfs/super.c-1371-\tfree_anon_bdev(dev);\n"
} |
| 21/2 | 2026/09/09 21:13 | llm | patch-evaluator |
0mModel:gemini-3.7-flash Args: null Results: null Tokens: input: 26022 output: 204 thoughts: 1190 Thoughts: **Fuzzing Analysis: Superblock Lifecycle and Synchronization** Okay, let's take a look at this patch. My initial thought is to examine functions related to superblock lifecycle and synchronization, specifically focusing on `deactivate_locked_super`, `deactivate_super`, `kill_anon_super`, `put_super`, `sget_fc`, and `kernfs_kill_sb`. I'm interested in how `put_super` is used; is it a ubiquitous function, or is its usage more specific? It looks like `put_super` is only called when passively releasing a superblock, like during unmount or when `sget_fc` or `super_dev_put` fail, which makes it less ubiquitous. The key function for filtering and handling `SB_DEAD` superblocks seems to be `sget_fc`. I'm also noting that `deactivate_locked_super` is the point where active references drop to zero, triggering `kill_sb`. `kill_anon_super` calls `kill_super_notify`, which is also important, as is `kernfs_kill_sb`, which in turn calls `kill_anon_super`. Now, I want to map out how these functions interact. We have `sget_fc` for superblock lookup and creation, `put_super` for passive refcount drops and deletion, `deactivate_locked_super` for deactivation, `kill_anon_super` for teardown, and `kernfs_kill_sb` for kernfs-specific shutdown. I'll also consider `generic_shutdown_super` in this context. Checking the patch, I see these symbols: `fs/kernfs/mount.c:kernfs_kill_sb`, `fs/super.c:put_super`, `fs/super.c:kill_super_notify`, `fs/super.c:deactivate_locked_super`, `fs/super.c:generic_shutdown_super`, and `fs/super.c:sget_fc`. Next, I need to check for any required configurations. `fs/super.c` is always compiled in, but `fs/kernfs/mount.c` is compiled when `KERNFS` is set. So, `KERNFS` is a relevant configuration to consider. It's boolean, often selected, and needs to be included. `fs/super.c` itself doesn't depend on any config options. Let's review the required outputs. We have `WorthFuzzing`, `Reasoning`, `FocusSymbols`, and `EnableConfigs`. For `FocusSymbols`, I've decided on: `sget_fc`, `put_super`, `deactivate_locked_super`, `generic_shutdown_super`, `kill_super_notify` (important, even though it's static – the compiler may retain it or we can consider its callers), `kill_anon_super`, and `kernfs_kill_sb`. This selection covers both the modified functions and the non-static callers of the static helpers. For `EnableConfigs`, it's just `KERNFS`. Here's my concise reasoning: The patch touches core VFS superblock lifecycle and synchronization during mount/unmount. It changes how superblocks are unlinked, synchronizes `SB_DEAD` status under `sb_lock`, moves `put_filesystem()` to `put_super()`, and updates `sget_fc()` to avoid `SB_DEAD` superblocks. This involves complex concurrency between mounting and unmounting processes, making it a good candidate for fuzzing to uncover potential race conditions or assertion failures. Now, let's call `set-results`. |
| 22/2 | 2026/09/09 21:13 | tool | set-results |
0mArgs:{
"EnableConfigs": [
"KERNFS"
],
"FocusSymbols": [
"sget_fc",
"put_super",
"deactivate_locked_super",
"generic_shutdown_super",
"kill_anon_super",
"kernfs_kill_sb"
],
"Reasoning": "The patch modifies core VFS superblock lifecycle and concurrency management across mount and unmount paths (in fs/super.c and fs/kernfs/mount.c). It defers unlinking superblocks from fs_supers until the last passive reference drops in put_super(), sets SB_DEAD under sb_lock in kill_super_notify(), and skips SB_DEAD superblocks during sget_fc() traversal. These changes alter concurrency invariants between concurrent mount (sget_fc) and shutdown/deactivation routines, making this core subsystem code well worth fuzzing for synchronization and reference counting regressions.",
"WorthFuzzing": true
}Results: {
"EnableConfigs": [
"KERNFS"
],
"FocusSymbols": [
"sget_fc",
"put_super",
"deactivate_locked_super",
"generic_shutdown_super",
"kill_anon_super",
"kernfs_kill_sb"
],
"Reasoning": "The patch modifies core VFS superblock lifecycle and concurrency management across mount and unmount paths (in fs/super.c and fs/kernfs/mount.c). It defers unlinking superblocks from fs_supers until the last passive reference drops in put_super(), sets SB_DEAD under sb_lock in kill_super_notify(), and skips SB_DEAD superblocks during sget_fc() traversal. These changes alter concurrency invariants between concurrent mount (sget_fc) and shutdown/deactivation routines, making this core subsystem code well worth fuzzing for synchronization and reference counting regressions.",
"WorthFuzzing": true
} |
| 23/1 | 2026/09/09 21:13 | action | If |
0mArgs:{
"WorthFuzzing": true
}Results: null |
| 24/2 | 2026/09/09 21:13 | agent | kmsan-evaluator |
0mModel:core Args: null Results: {
"KMSANReasoning": "The patch modifies the lifecycle management and synchronization of superblock instances (fs/super.c and fs/kernfs/mount.c) across mount and shutdown paths (sget_fc, kill_super_notify, put_super). It defers unlinking sb-\u003es_instances and put_filesystem to put_super, while holding sb_lock when setting SB_DEAD so concurrent sget_fc() calls skip dying superblocks.\n\nThese changes deal strictly with reference counting, locking (sb_lock), list management, and object lifecycle synchronization. Any potential regressions or bugs introduced here (such as use-after-free, race conditions, or locking issues) are tracked by KASAN, LOCKDEP, and standard kernel debugging facilities. No uninitialized memory, buffer parsing, or kernel-to-userspace copying is introduced or modified. Therefore, a dedicated KMSAN fuzzing session is not warranted.",
"NeedsKMSAN": false
}Instruction: You are an expert Linux kernel security engineer specializing in kernel memory
error detectors (KASAN and KMSAN). Your job is to review the provided patch series and
determine if the code changes justify spawning a dedicated KMSAN (KernelMemorySanitizer)
fuzzing session in addition to standard KASAN fuzzing.
CRITICAL DISTINCTION BETWEEN KASAN AND KMSAN:
- Standard KASAN kernel builds (upstream-apparmor-kasan.config) already enable
a comprehensive suite of debugging tools and sanitizers, including KASAN
(out-of-bounds accesses, use-after-free, double free, invalid free), LOCKDEP
(locking bugs and deadlocks), UB-sanitizers, and memory corruption checks.
- KMSAN (KernelMemorySanitizer) detects reads of UNINITIALIZED memory (stack, heap,
or page allocations) and kernel-to-user memory info-leaks.
Rule: THERE IS NO SENSE IN RUNNING A KMSAN SESSION IF A BUG CAN BE CAUGHT BY KASAN,
LOCKDEP, OR OTHER STANDARD BUG DETECTORS.
A dedicated KMSAN fuzzing session incurs significant resource costs. You must ONLY
set NeedsKMSAN=true if the code changes introduce or expose UNINITIALIZED MEMORY risks
that are detected ONLY by KMSAN.
Look holistically at the patch series and surrounding code. Even if no direct
uninitialized field accesses or new buffer allocations are added in the diff itself,
a patch may alter control flow, bounds checking, or data length calculations in ways
that change how the rest of the code operates on existing buffers (e.g. allowing
uninitialized stack/heap memory to be read, copied to user space, or used in control
flow). Do not hesitate to use your code access tools to inspect the surrounding code,
called functions, and callers.
Set NeedsKMSAN=true ONLY IF the patch introduces or modifies:
1. Kernel structures sent to user space (via copy_to_user, put_user, netlink skb
attributes, ioctl output arguments, socket options, or BPF buffers) where fields
or structure padding might not be fully initialized/zeroed.
2. Conditional logic or branching that depends on potentially uninitialized variables
or struct fields.
3. Allocation or initialization of complex data structures where uninitialized fields
could be read later in reachable code paths.
4. Bounds checks, lengths, or logic in a way that allows surrounding code to access
uninitialized bytes of existing buffers.
Set NeedsKMSAN=false IF:
- The code changes primarily risk out-of-bounds access, array overflows, NULL pointer
dereferences, locking deadlocks, or use-after-free bugs (these are already caught
by KASAN, LOCKDEP, or standard bug detectors).
- All stack/heap structures touched or introduced by the patch are fully zeroed
or initialized (e.g. using = {0}, memset, kzalloc) before being read or copied.
- The patch does not introduce any risk of uninitialized memory usage or info-leaks.
Use your code access tools to inspect the surrounding code if necessary, then provide
detailed KMSANReasoning contrasting KASAN vs KMSAN applicability for this patch.
Prefer calling several tools at the same time to save round-trips.
Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.
Prompt: Target architecture: amd64
For your convenience, here is the diff of the changes:
commit c9c7f033e1743e33ebdeb8b896db27baf54d70a8
Author: syz-cluster <triage@syzkaller.com>
Date: Wed Sep 9 21:12:32 2026 +0000
syz-cluster: applied patch under review
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index f183a96778b9a..a57399021c8b0 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -434,8 +434,8 @@ void kernfs_kill_sb(struct super_block *sb)
up_write(&root->kernfs_supers_rwsem);
/*
- * Remove the superblock from fs_supers/s_instances
- * so we can't find it, before freeing kernfs_super_info.
+ * Mark the superblock dead so sget_fc() can't find it,
+ * before freeing kernfs_super_info.
*/
kill_anon_super(sb);
kfree(info);
diff --git a/fs/super.c b/fs/super.c
index 05e4431730387..0f9e13eedb4fb 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -433,15 +433,19 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags,
void put_super(struct super_block *s)
{
if (refcount_dec_and_test(&s->s_passive)) {
+ struct file_system_type *type = s->s_type;
spin_lock(&sb_lock);
list_del_init(&s->s_list);
+ hlist_del_init(&s->s_instances);
spin_unlock(&sb_lock);
WARN_ON(s->s_dentry_lru.node);
WARN_ON(s->s_inode_lru.node);
WARN_ON(s->s_mounts);
call_rcu(&s->rcu, destroy_super_rcu);
+ /* The unlink above may touch type->fs_supers, so drop it last. */
+ put_filesystem(type);
}
}
@@ -558,17 +562,6 @@ static void kill_super_notify(struct super_block *sb)
if (sb->s_flags & SB_DEAD)
return;
- /*
- * Remove it from @fs_supers so it isn't found by new
- * sget_fc() walkers anymore. Any concurrent mounter still
- * managing to grab a temporary reference is guaranteed to
- * already see SB_DYING and will wait until we notify them about
- * SB_DEAD.
- */
- spin_lock(&sb_lock);
- hlist_del_init(&sb->s_instances);
- spin_unlock(&sb_lock);
-
/* Drop sget_fc()'s claim; a never-registered entry stays with the sb. */
if (sb->s_super_dev->sd_dev) {
super_dev_put(sb->s_super_dev);
@@ -577,11 +570,15 @@ static void kill_super_notify(struct super_block *sb)
/*
* Let concurrent mounts know that this thing is really dead.
- * We don't need @sb->s_umount here as every concurrent caller
- * will see SB_DYING and either discard the superblock or wait
- * for SB_DEAD.
+ * sget_fc() skips SB_DEAD superblocks and calls test() under
+ * sb_lock, so set it under sb_lock: once we return no test()
+ * runs on this superblock anymore and none will start. Everyone
+ * else already saw SB_DYING and either discarded the superblock
+ * or waits for SB_DEAD.
*/
+ spin_lock(&sb_lock);
super_wake(sb, SB_DEAD);
+ spin_unlock(&sb_lock);
}
/**
@@ -608,7 +605,6 @@ void deactivate_locked_super(struct super_block *s)
list_lru_destroy(&s->s_dentry_lru);
list_lru_destroy(&s->s_inode_lru);
- put_filesystem(fs);
put_super(s);
} else {
super_unlock_excl(s);
@@ -795,12 +791,12 @@ void generic_shutdown_super(struct super_block *sb)
}
/*
* Broadcast to everyone that grabbed a temporary reference to this
- * superblock before we removed it from @fs_supers that the superblock
- * is dying. Every walker of @fs_supers outside of sget_fc() will now
- * discard this superblock and treat it as dead.
+ * superblock that it is dying. Every walker of @fs_supers outside
+ * of sget_fc() will now discard this superblock and treat it as
+ * dead.
*
- * We leave the superblock on @fs_supers so it can be found by
- * sget_fc() until we passed sb->kill_sb().
+ * sget_fc() keeps finding the superblock until SB_DEAD is set, so
+ * a concurrent mounter waits until we passed sb->kill_sb().
*/
super_wake(sb, SB_DYING);
super_unlock_excl(sb);
@@ -879,6 +875,9 @@ struct super_block *sget_fc(struct fs_context *fc,
spin_lock(&sb_lock);
if (test) {
hlist_for_each_entry(old, &fc->fs_type->fs_supers, s_instances) {
+ /* Only unlinked at the last passive reference. */
+ if (super_flags(old, SB_DEAD))
+ continue;
if (test(old, fc))
goto share_extant_sb;
}
|
| 25/3 | 2026/09/09 21:13 | llm | kmsan-evaluator |
0mModel:gemini-3.7-flash Args: null Results: null Tokens: input: 3399 output: 212 thoughts: 1217 Thoughts: **KMSAN Fuzzing Session Assessment** Alright, let's break down this patch and figure out if it's worth a KMSAN fuzzing run. The changes touch `fs/kernfs/mount.c` and `fs/super.c`, so we're dealing with superblock stuff. Looking at the code, it seems like a rework of the superblock lifecycle and synchronization, specifically dealing with the interaction between `sget_fc`, `kill_super_notify`, `put_super`, and related functions. The patch defers `hlist_del_init` of `s_instances` and adds a `SB_DEAD` check in `sget_fc`. There are also some `put_filesystem` calls being moved. It's a synchronization and lifecycle refactor, essentially. Now, for KMSAN, we need to ask, does this introduce risks related to uninitialized memory? Does it expose kernel data to userspace without proper initialization? No, the patch doesn't seem to touch any uninitialized stack or heap memory. It's not copying data to userspace, and it doesn't appear to be involved in any new memory initialization or the introduction of uninitialized struct fields. This patch seems to be about addressing concurrency issues, races, and maybe refcount problems, use-after-free conditions, or list corruption. Now, let's check the guidelines. The guidelines make it very clear: if a bug can be detected by KASAN, LOCKDEP, or other standard detectors, a KMSAN session is pointless. KASAN is built to catch out-of-bounds accesses, use-after-free, double frees, invalid frees. Lockdep is good for locking bugs. This patch deals with synchronization, concurrency, list manipulation, and lifecycle management. It's about preventing race conditions, use-after-free, and list corruption. The patch does not deal with uninitialized memory issues. Therefore, because this refactoring touches synchronization, list manipulation, and superblock lifecycle, the risks are around concurrency races, use-after-free, or list corruption, all of which fall firmly under KASAN/LOCKDEP. There's no KMSAN risk here. So, `NeedsKMSAN = false`. Time to prepare the `set-results` tool call. |
| 26/3 | 2026/09/09 21:13 | tool | set-results |
0mArgs:{
"KMSANReasoning": "The patch modifies the lifecycle management and synchronization of superblock instances (fs/super.c and fs/kernfs/mount.c) across mount and shutdown paths (sget_fc, kill_super_notify, put_super). It defers unlinking sb-\u003es_instances and put_filesystem to put_super, while holding sb_lock when setting SB_DEAD so concurrent sget_fc() calls skip dying superblocks.\n\nThese changes deal strictly with reference counting, locking (sb_lock), list management, and object lifecycle synchronization. Any potential regressions or bugs introduced here (such as use-after-free, race conditions, or locking issues) are tracked by KASAN, LOCKDEP, and standard kernel debugging facilities. No uninitialized memory, buffer parsing, or kernel-to-userspace copying is introduced or modified. Therefore, a dedicated KMSAN fuzzing session is not warranted.",
"NeedsKMSAN": false
}Results: {
"KMSANReasoning": "The patch modifies the lifecycle management and synchronization of superblock instances (fs/super.c and fs/kernfs/mount.c) across mount and shutdown paths (sget_fc, kill_super_notify, put_super). It defers unlinking sb-\u003es_instances and put_filesystem to put_super, while holding sb_lock when setting SB_DEAD so concurrent sget_fc() calls skip dying superblocks.\n\nThese changes deal strictly with reference counting, locking (sb_lock), list management, and object lifecycle synchronization. Any potential regressions or bugs introduced here (such as use-after-free, race conditions, or locking issues) are tracked by KASAN, LOCKDEP, and standard kernel debugging facilities. No uninitialized memory, buffer parsing, or kernel-to-userspace copying is introduced or modified. Therefore, a dedicated KMSAN fuzzing session is not warranted.",
"NeedsKMSAN": false
} |
| Total Calls | Total Tokens | Avg Tokens | Total Duration (Seconds) | Avg Duration (Seconds) |
|---|
| Total Calls | Total Duration (Seconds) | Avg Duration (Seconds) |
|---|