The OCFS2 debugfs file operation tables do not set owner. The full debugfs proxy obtains real_fops with fops_get() at open and keeps it until final release. Without an owner, this does not acquire a reference to the module containing the table and its callbacks. Removing the debugfs entries does not drain retained open files. An open connected_nodes file can therefore outlive ocfs2_nodemanager and make full_proxy_release() read real_fops->release from freed module memory. Heming also reproduced the issue with fs_state and asked for the other OCFS2 debugfs operation tables to be checked. Set owner to THIS_MODULE in all eleven explicit debugfs operation tables: five in ocfs2_nodemanager, four in ocfs2_dlm, and two in ocfs2. The existing debugfs get/put pair then holds the appropriate module until final release. Leave the open, read and release callbacks unchanged. The blockcheck table already sets owner through DEFINE_DEBUGFS_ATTRIBUTE(), so it needs no change. The original controlled test used an unloadable OCFS2 module and case-local probe filters without changing the candidate open, unload or release logic. Closing a retained connected_nodes file after normal unload produced: BUG: unable to handle page fault for address: fffffbfff804cfef Oops: Oops: 0000 [#1] SMP KASAN NOPTI RIP: 0010:full_proxy_release+0xbf/0x190 Call Trace: __fput+0x39a/0xa60 fput_close_sync+0xff/0x200 __x64_sys_close+0x8c/0xf0 do_syscall_64+0x114/0x620 entry_SYSCALL_64_after_hwframe+0x77/0x7f Modules linked in: [last unloaded: ocfs2_nodemanager] Fixes: 2309e9e040fe ("ocfs2/net: Add debug interface to o2net") Fixes: db02754c8a12 ("ocfs2/cluster: Show o2net timing statistics") Fixes: 87d3d3f3931f ("ocfs2/hb: Expose the list of heartbeating nodes via debugfs") Fixes: 3ba169ccec1c ("ocfs2/cluster: Add new function o2net_fill_node_map()") Fixes: 50397507e856 ("ocfs2: Expose the file system state via debugfs") Fixes: ccd979bdbce9 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem") Fixes: 7209300a9b98 ("ocfs2/dlm: Dumps the purgelist into a debugfs file") Fixes: d0129aceaecc ("ocfs2/dlm: Dumps the mles into a debugfs file") Fixes: 4e3d24ed1a12 ("ocfs2/dlm: Dumps the lockres' into a debugfs file") Fixes: 007dce53a29c ("ocfs2/dlm: Dump the dlm state in a debugfs file") Assisted-by: LLM Cc: Suggested-by: Heming Zhao Reviewed-by: Joseph Qi Signed-off-by: Cen Zhang --- Changes in v4: - Add the missing Fixes tag for stats_seq_fops: db02754c8a12 ("ocfs2/cluster: Show o2net timing statistics"). - Add Joseph Qi's Reviewed-by; keep the code unchanged. Changes in v3: - Match each .owner assignment to the indentation of neighboring members throughout, as requested by Kees Cook. Changes in v2: - Cover fs_state and locking_state in the OCFS2 filesystem module. - Cover all four OCFS2 DLM debugfs operation tables. - Keep the five node manager fixes and the original diagnostic. - Add explicit module headers and Fixes tags for the added tables. - Add Cc: stable@vger.kernel.org. Link to v1: https://lore.kernel.org/r/pm-ocfs2-objects-candidate-0089-v2-4c67f48d4e2d0fc85990@gmail.com Link to v2: https://lore.kernel.org/r/pm-ocfs2-objects-candidate-0089-v5-076c780eeaf45afb2a53@gmail.com Link to v3: https://lore.kernel.org/r/pm-ocfs2-objects-candidate-0089-v6-f7fda843f80887488145@gmail.com fs/ocfs2/cluster/heartbeat.c | 1 + fs/ocfs2/cluster/netdebug.c | 4 ++++ fs/ocfs2/dlm/dlmdebug.c | 5 +++++ fs/ocfs2/dlmglue.c | 2 ++ fs/ocfs2/super.c | 1 + 5 files changed, 13 insertions(+) diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c index 8e6ead433228e7419bfbbe5c7cdde65c654a24f4..1cb516df53f4e1b3b2a292eb2550faa3d16e3fa2 100644 --- a/fs/ocfs2/cluster/heartbeat.c +++ b/fs/ocfs2/cluster/heartbeat.c @@ -1447,6 +1447,7 @@ static ssize_t o2hb_debug_read(struct file *file, char __user *buf, #endif /* CONFIG_DEBUG_FS */ static const struct file_operations o2hb_debug_fops = { + .owner = THIS_MODULE, .open = o2hb_debug_open, .release = o2hb_debug_release, .read = o2hb_debug_read, diff --git a/fs/ocfs2/cluster/netdebug.c b/fs/ocfs2/cluster/netdebug.c index f7ab66e70799302f3ed4e70ab6a8fb057dd0bfa9..5d373002297de1fdd9a05e270f7942d8c1ce2dac 100644 --- a/fs/ocfs2/cluster/netdebug.c +++ b/fs/ocfs2/cluster/netdebug.c @@ -183,6 +183,7 @@ static int nst_fop_release(struct inode *inode, struct file *file) } static const struct file_operations nst_seq_fops = { + .owner = THIS_MODULE, .open = nst_fop_open, .read = seq_read, .llseek = seq_lseek, @@ -415,6 +416,7 @@ static int stats_fop_open(struct inode *inode, struct file *file) } static const struct file_operations stats_seq_fops = { + .owner = THIS_MODULE, .open = stats_fop_open, .read = seq_read, .llseek = seq_lseek, @@ -427,6 +429,7 @@ static int sc_fop_open(struct inode *inode, struct file *file) } static const struct file_operations sc_seq_fops = { + .owner = THIS_MODULE, .open = sc_fop_open, .read = seq_read, .llseek = seq_lseek, @@ -476,6 +479,7 @@ static ssize_t o2net_debug_read(struct file *file, char __user *buf, } static const struct file_operations nodes_fops = { + .owner = THIS_MODULE, .open = nodes_fop_open, .release = o2net_debug_release, .read = o2net_debug_read, diff --git a/fs/ocfs2/dlm/dlmdebug.c b/fs/ocfs2/dlm/dlmdebug.c index ce6d301cb9420385211d20d59637069154a89993..8919eb14df22700b36b1edf985bca15b8f185fd6 100644 --- a/fs/ocfs2/dlm/dlmdebug.c +++ b/fs/ocfs2/dlm/dlmdebug.c @@ -7,6 +7,7 @@ * Copyright (C) 2004, 2008 Oracle. All rights reserved. */ +#include #include #include #include @@ -339,6 +340,7 @@ static int debug_purgelist_open(struct inode *inode, struct file *file) } static const struct file_operations debug_purgelist_fops = { + .owner = THIS_MODULE, .open = debug_purgelist_open, .release = debug_release, .read = debug_read, @@ -394,6 +396,7 @@ static int debug_mle_open(struct inode *inode, struct file *file) } static const struct file_operations debug_mle_fops = { + .owner = THIS_MODULE, .open = debug_mle_open, .release = debug_release, .read = debug_read, @@ -601,6 +604,7 @@ static int debug_lockres_release(struct inode *inode, struct file *file) } static const struct file_operations debug_lockres_fops = { + .owner = THIS_MODULE, .open = debug_lockres_open, .release = debug_lockres_release, .read = seq_read, @@ -791,6 +795,7 @@ static int debug_state_open(struct inode *inode, struct file *file) } static const struct file_operations debug_state_fops = { + .owner = THIS_MODULE, .open = debug_state_open, .release = debug_release, .read = debug_read, diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c index 6bc4a21cf5f02f04a6b54100925084aed239ae62..88d9464660833006b7bac25e2c2641dd77874438 100644 --- a/fs/ocfs2/dlmglue.c +++ b/fs/ocfs2/dlmglue.c @@ -7,6 +7,7 @@ * Copyright (C) 2003, 2004 Oracle. All rights reserved. */ +#include #include #include #include @@ -3332,6 +3333,7 @@ static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file) } static const struct file_operations ocfs2_dlm_debug_fops = { + .owner = THIS_MODULE, .open = ocfs2_dlm_debug_open, .release = ocfs2_dlm_debug_release, .read = seq_read, diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index 1e76b1d9fe0af4b3cf503e91e1dd077762fef88a..0af2245ae30369421e78ecd781b986c481d10f5b 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -387,6 +387,7 @@ static ssize_t ocfs2_debug_read(struct file *file, char __user *buf, #endif /* CONFIG_DEBUG_FS */ static const struct file_operations ocfs2_osb_debug_fops = { + .owner = THIS_MODULE, .open = ocfs2_osb_debug_open, .release = ocfs2_debug_release, .read = ocfs2_debug_read,