| Seq | Timestamp | Type | Name | Duration |
|---|---|---|---|---|
| 0/0 | 2026/10/04 05:19 | flow | patch-triage |
1mArgs:null Results: {
"EnableConfigs": [
"CRYPTO_LIB_CHACHA20POLY1305",
"WIREGUARD",
"BIG_KEYS"
],
"FocusSymbols": [
"chacha20poly1305_decrypt",
"xchacha20poly1305_decrypt",
"__chacha20poly1305_decrypt"
],
"KMSANReasoning": "The patch moves the zeroization of `chacha_state` via `chacha_zeroize_state()` into `__chacha20poly1305_decrypt()`, ensuring the ChaCha state is wiped on all exit paths (including the early-return path when `src_len \u003c POLY1305_DIGEST_SIZE`) and for all callers (including `xchacha20poly1305_decrypt()`).\n\nThis is a cryptographic hygiene change that only explicitly zeroes out memory buffers before returning. It does not introduce, read, branch on, or leak uninitialized memory to user space, nor does it alter memory allocation or buffer bounds. Therefore, KMSAN is not applicable.",
"NeedsKMSAN": false,
"Reasoning": "The patch modifies executable crypto code in lib/crypto/chacha20poly1305.c by moving chacha_zeroize_state() into __chacha20poly1305_decrypt(), ensuring sensitive cipher state is cleared on early return and for all callers including xchacha20poly1305_decrypt(). The modified routines are reachable via virtual network devices (WireGuard) and keyrings (big_key), making it suitable for fuzzing.",
"WorthFuzzing": true
} |
| 1/1 | 2026/10/04 05:19 | action | read-patch-diff |
0mArgs:null Results: {
"PatchDiff": "commit fba883ec5c7801fa6bfe973fa73cb8647f14d638\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate: Sun Oct 4 05:19:52 2026 +0000\n\n syz-cluster: applied patch under review\n\ndiff --git a/lib/crypto/chacha20poly1305.c b/lib/crypto/chacha20poly1305.c\nindex ea42a28f4ff7d..80904321458b4 100644\n--- a/lib/crypto/chacha20poly1305.c\n+++ b/lib/crypto/chacha20poly1305.c\n@@ -137,8 +137,10 @@ __chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\n \t\t__le64 lens[2];\n \t} b;\n \n-\tif (unlikely(src_len \u003c POLY1305_DIGEST_SIZE))\n+\tif (unlikely(src_len \u003c POLY1305_DIGEST_SIZE)) {\n+\t\tchacha_zeroize_state(chacha_state);\n \t\treturn false;\n+\t}\n \n \tchacha20_crypt(chacha_state, b.block0, pad0, sizeof(b.block0));\n \tpoly1305_init(\u0026poly1305_state, b.block0);\n@@ -164,6 +166,7 @@ __chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\n \n \tmemzero_explicit(\u0026b, sizeof(b));\n \n+\tchacha_zeroize_state(chacha_state);\n \treturn !ret;\n }\n \n@@ -186,7 +189,6 @@ bool chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\n \tret = __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,\n \t\t\t\t\t \u0026chacha_state);\n \n-\tchacha_zeroize_state(\u0026chacha_state);\n \tmemzero_explicit(iv, sizeof(iv));\n \tmemzero_explicit(k, sizeof(k));\n \treturn ret;\n"
} |
| 2/1 | 2026/10/04 05:19 | agent | patch-evaluator |
1mModel:core Args: null Results: {
"EnableConfigs": [
"CRYPTO_LIB_CHACHA20POLY1305",
"WIREGUARD",
"BIG_KEYS"
],
"FocusSymbols": [
"chacha20poly1305_decrypt",
"xchacha20poly1305_decrypt",
"__chacha20poly1305_decrypt"
],
"Reasoning": "The patch modifies executable crypto code in lib/crypto/chacha20poly1305.c by moving chacha_zeroize_state() into __chacha20poly1305_decrypt(), ensuring sensitive cipher state is cleared on early return and for all callers including xchacha20poly1305_decrypt(). The modified routines are reachable via virtual network devices (WireGuard) and keyrings (big_key), making it suitable for fuzzing.",
"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 fba883ec5c7801fa6bfe973fa73cb8647f14d638
Author: syz-cluster <triage@syzkaller.com>
Date: Sun Oct 4 05:19:52 2026 +0000
syz-cluster: applied patch under review
diff --git a/lib/crypto/chacha20poly1305.c b/lib/crypto/chacha20poly1305.c
index ea42a28f4ff7d..80904321458b4 100644
--- a/lib/crypto/chacha20poly1305.c
+++ b/lib/crypto/chacha20poly1305.c
@@ -137,8 +137,10 @@ __chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
__le64 lens[2];
} b;
- if (unlikely(src_len < POLY1305_DIGEST_SIZE))
+ if (unlikely(src_len < POLY1305_DIGEST_SIZE)) {
+ chacha_zeroize_state(chacha_state);
return false;
+ }
chacha20_crypt(chacha_state, b.block0, pad0, sizeof(b.block0));
poly1305_init(&poly1305_state, b.block0);
@@ -164,6 +166,7 @@ __chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
memzero_explicit(&b, sizeof(b));
+ chacha_zeroize_state(chacha_state);
return !ret;
}
@@ -186,7 +189,6 @@ bool chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
ret = __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,
&chacha_state);
- chacha_zeroize_state(&chacha_state);
memzero_explicit(iv, sizeof(iv));
memzero_explicit(k, sizeof(k));
return ret;
|
| 3/2 | 2026/10/04 05:19 | llm | patch-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 3180 output: 42 thoughts: 94 Thoughts: Here's my thought process, as if I were analyzing this patch: **Analyzing the Chacha20-Poly1305 Patch** Okay, let's dive in. First, I need to understand the scope of this change. It looks like this patch is specifically targeting `lib/crypto/chacha20poly1305.c`. My immediate thought is, "Right, let's get a handle on the existing code." I'll probably use `git grep` to see what's changed or `read-file` to zero in on the exact context. Given that I'm aiming for targeted analysis, let's just go with `read-file` to get a precise look. I'm going to focus on around line 137. That's a good starting point, and I can always broaden my scope if it seems necessary. Let's see what we can find. |
| 4/2 | 2026/10/04 05:20 | tool | read-file |
0mArgs:{
"File": "lib/crypto/chacha20poly1305.c",
"FirstLine": 120,
"LineCount": 80
}Results: {
"Contents": " 120:\t\t__chacha20poly1305_encrypt(dst, src, src_len, ad, ad_len,\n 121:\t\t\t\t\t \u0026chacha_state);\n 122:\t}\n 123:\tEXPORT_SYMBOL(xchacha20poly1305_encrypt);\n 124:\t\n 125:\tstatic bool\n 126:\t__chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\n 127:\t\t\t\t const u8 *ad, const size_t ad_len,\n 128:\t\t\t\t struct chacha_state *chacha_state)\n 129:\t{\n 130:\t\tconst u8 *pad0 = page_address(ZERO_PAGE(0));\n 131:\t\tstruct poly1305_desc_ctx poly1305_state;\n 132:\t\tsize_t dst_len;\n 133:\t\tint ret;\n 134:\t\tunion {\n 135:\t\t\tu8 block0[POLY1305_KEY_SIZE];\n 136:\t\t\tu8 mac[POLY1305_DIGEST_SIZE];\n 137:\t\t\t__le64 lens[2];\n 138:\t\t} b;\n 139:\t\n 140:\t\tif (unlikely(src_len \u003c POLY1305_DIGEST_SIZE)) {\n 141:\t\t\tchacha_zeroize_state(chacha_state);\n 142:\t\t\treturn false;\n 143:\t\t}\n 144:\t\n 145:\t\tchacha20_crypt(chacha_state, b.block0, pad0, sizeof(b.block0));\n 146:\t\tpoly1305_init(\u0026poly1305_state, b.block0);\n 147:\t\n 148:\t\tpoly1305_update(\u0026poly1305_state, ad, ad_len);\n 149:\t\tif (ad_len \u0026 0xf)\n 150:\t\t\tpoly1305_update(\u0026poly1305_state, pad0, 0x10 - (ad_len \u0026 0xf));\n 151:\t\n 152:\t\tdst_len = src_len - POLY1305_DIGEST_SIZE;\n 153:\t\tpoly1305_update(\u0026poly1305_state, src, dst_len);\n 154:\t\tif (dst_len \u0026 0xf)\n 155:\t\t\tpoly1305_update(\u0026poly1305_state, pad0, 0x10 - (dst_len \u0026 0xf));\n 156:\t\n 157:\t\tb.lens[0] = cpu_to_le64(ad_len);\n 158:\t\tb.lens[1] = cpu_to_le64(dst_len);\n 159:\t\tpoly1305_update(\u0026poly1305_state, (u8 *)b.lens, sizeof(b.lens));\n 160:\t\n 161:\t\tpoly1305_final(\u0026poly1305_state, b.mac);\n 162:\t\n 163:\t\tret = crypto_memneq(b.mac, src + dst_len, POLY1305_DIGEST_SIZE);\n 164:\t\tif (likely(!ret))\n 165:\t\t\tchacha20_crypt(chacha_state, dst, src, dst_len);\n 166:\t\n 167:\t\tmemzero_explicit(\u0026b, sizeof(b));\n 168:\t\n 169:\t\tchacha_zeroize_state(chacha_state);\n 170:\t\treturn !ret;\n 171:\t}\n 172:\t\n 173:\tbool chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\n 174:\t\t\t\t const u8 *ad, const size_t ad_len,\n 175:\t\t\t\t const u64 nonce,\n 176:\t\t\t\t const u8 key[at_least CHACHA20POLY1305_KEY_SIZE])\n 177:\t{\n 178:\t\tstruct chacha_state chacha_state;\n 179:\t\tu32 k[CHACHA_KEY_WORDS];\n 180:\t\t__le64 iv[2];\n 181:\t\tbool ret;\n 182:\t\n 183:\t\tchacha_load_key(k, key);\n 184:\t\n 185:\t\tiv[0] = 0;\n 186:\t\tiv[1] = cpu_to_le64(nonce);\n 187:\t\n 188:\t\tchacha_init(\u0026chacha_state, k, (u8 *)iv);\n 189:\t\tret = __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,\n 190:\t\t\t\t\t\t \u0026chacha_state);\n 191:\t\n 192:\t\tmemzero_explicit(iv, sizeof(iv));\n 193:\t\tmemzero_explicit(k, sizeof(k));\n 194:\t\treturn ret;\n 195:\t}\n 196:\tEXPORT_SYMBOL(chacha20poly1305_decrypt);\n 197:\t\n 198:\tbool xchacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\n 199:\t\t\t\t const u8 *ad, const size_t ad_len,\n"
} |
| 5/2 | 2026/10/04 05:20 | llm | patch-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 4965 output: 42 thoughts: 34 Thoughts: Here's my summary, as if I were thinking these thoughts: **Diving into the `xchacha20poly1305_decrypt` Function** Alright, let's get into the heart of the decryption process. I need to understand what's happening within this `xchacha20poly1305_decrypt` function, so I'm going to focus on lines 195 through 225. Let's see how this implementation handles the details. This should give me the core of the algorithm, assuming this isn't a wrapper. Knowing this function will give me a more complete picture of how the overall cryptography is achieved. |
| 6/2 | 2026/10/04 05:20 | tool | read-file |
0mArgs:{
"File": "lib/crypto/chacha20poly1305.c",
"FirstLine": 195,
"LineCount": 40
}Results: {
"Contents": " 195:\t}\n 196:\tEXPORT_SYMBOL(chacha20poly1305_decrypt);\n 197:\t\n 198:\tbool xchacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\n 199:\t\t\t\t const u8 *ad, const size_t ad_len,\n 200:\t\t\t\t const u8 nonce[at_least XCHACHA20POLY1305_NONCE_SIZE],\n 201:\t\t\t\t const u8 key[at_least CHACHA20POLY1305_KEY_SIZE])\n 202:\t{\n 203:\t\tstruct chacha_state chacha_state;\n 204:\t\n 205:\t\txchacha_init(\u0026chacha_state, key, nonce);\n 206:\t\treturn __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,\n 207:\t\t\t\t\t\t \u0026chacha_state);\n 208:\t}\n 209:\tEXPORT_SYMBOL(xchacha20poly1305_decrypt);\n 210:\t\n 211:\tstatic\n 212:\tbool chacha20poly1305_crypt_sg_inplace(struct scatterlist *src,\n 213:\t\t\t\t\t const size_t src_len,\n 214:\t\t\t\t\t const u8 *ad, const size_t ad_len,\n 215:\t\t\t\t\t const u64 nonce,\n 216:\t\t\t\t\t const u8 key[at_least CHACHA20POLY1305_KEY_SIZE],\n 217:\t\t\t\t\t int encrypt)\n 218:\t{\n 219:\t\tconst u8 *pad0 = page_address(ZERO_PAGE(0));\n 220:\t\tstruct poly1305_desc_ctx poly1305_state;\n 221:\t\tstruct chacha_state chacha_state;\n 222:\t\tstruct sg_mapping_iter miter;\n 223:\t\tsize_t partial = 0;\n 224:\t\tunsigned int flags;\n 225:\t\tbool ret = true;\n 226:\t\tint sl;\n 227:\t\tunion {\n 228:\t\t\tstruct {\n 229:\t\t\t\tu32 k[CHACHA_KEY_WORDS];\n 230:\t\t\t\t__le64 iv[2];\n 231:\t\t\t};\n 232:\t\t\tu8 block0[POLY1305_KEY_SIZE];\n 233:\t\t\tu8 chacha_stream[CHACHA_BLOCK_SIZE];\n 234:\t\t\tstruct {\n"
} |
| 7/2 | 2026/10/04 05:20 | llm | patch-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 5879 output: 27 thoughts: 225 Thoughts: **Analyzing the Chacha20-Poly1305 Decryption Implementation** Okay, let's dive into this `xchacha20poly1305_decrypt` function. My initial observation is that it calls `__chacha20poly1305_decrypt`, passing in the destination buffer, source buffer, lengths, and associated data, along with a `chacha_state`. However, a crucial difference jumps out at me compared to the standard `chacha20poly1305_decrypt` function. The latter *does* zero out the `chacha_state` beforehand, but `xchacha20poly1305_decrypt` *doesn't*! Now, digging deeper into `__chacha20poly1305_decrypt`, I see a potential vulnerability. If `src_len` is less than `POLY1305_DIGEST_SIZE`, the function immediately returns `false` due to insufficient data for the Poly1305 authentication tag. The critical thing here is that *it doesn't zero out the `chacha_state` in this error path*! This is a serious concern, as it could leak sensitive information if not handled properly. The patch seems to address this by moving `chacha_zeroize_state(chacha_state);` *inside* `__chacha20poly1305_decrypt`. It's now being called both in the error return path (when `src_len` is too small) *and* at the end of the function, ensuring that the ChaCha state is consistently zeroed regardless of success or failure. This makes sense from a security perspective, protecting against potential side-channel attacks by clearing the state. Now, I need to check the call sites. Let's see who is using both `chacha20poly1305_decrypt` and `xchacha20poly1305_decrypt` to ensure that this change is propagated correctly and to assess the impact of this potential flaw. |
| 8/2 | 2026/10/04 05:20 | tool | grepper |
0mArgs:{
"Expression": "(x)?chacha20poly1305_decrypt"
}Results: {
"Output": "drivers/net/wireguard/cookie.c=198=void wg_cookie_message_consume(struct message_handshake_cookie *src,\n--\ndrivers/net/wireguard/cookie.c-215-\t}\ndrivers/net/wireguard/cookie.c:216:\tret = xchacha20poly1305_decrypt(\ndrivers/net/wireguard/cookie.c-217-\t\tcookie, src-\u003eencrypted_cookie, sizeof(src-\u003eencrypted_cookie),\n--\ndrivers/net/wireguard/noise.c=473=static bool message_decrypt(u8 *dst_plaintext, const u8 *src_ciphertext,\n--\ndrivers/net/wireguard/noise.c-476-{\ndrivers/net/wireguard/noise.c:477:\tif (!chacha20poly1305_decrypt(dst_plaintext, src_ciphertext, src_len,\ndrivers/net/wireguard/noise.c-478-\t\t\t\t hash, NOISE_HASH_LEN,\n--\ndrivers/net/wireguard/receive.c=242=static bool decrypt_packet(struct sk_buff *skb, struct noise_keypair *keypair)\n--\ndrivers/net/wireguard/receive.c-277-\ndrivers/net/wireguard/receive.c:278:\tif (!chacha20poly1305_decrypt_sg_inplace(sg, skb-\u003elen, NULL, 0,\ndrivers/net/wireguard/receive.c-279-\t\t\t\t\t PACKET_CB(skb)-\u003enonce,\n--\ninclude/crypto/chacha20poly1305.h=23=bool __must_check\ninclude/crypto/chacha20poly1305.h:24:chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\ninclude/crypto/chacha20poly1305.h-25-\t\t\t const u8 *ad, const size_t ad_len, const u64 nonce,\n--\ninclude/crypto/chacha20poly1305.h=28=void xchacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,\n--\ninclude/crypto/chacha20poly1305.h-32-\ninclude/crypto/chacha20poly1305.h:33:bool __must_check xchacha20poly1305_decrypt(\ninclude/crypto/chacha20poly1305.h-34-\tu8 *dst, const u8 *src, const size_t src_len,\n--\ninclude/crypto/chacha20poly1305.h=39=bool chacha20poly1305_encrypt_sg_inplace(struct scatterlist *src, size_t src_len,\n--\ninclude/crypto/chacha20poly1305.h-43-\ninclude/crypto/chacha20poly1305.h:44:bool chacha20poly1305_decrypt_sg_inplace(struct scatterlist *src, size_t src_len,\ninclude/crypto/chacha20poly1305.h-45-\t\t\t\t\t const u8 *ad, const size_t ad_len,\n--\nlib/crypto/chacha20poly1305.c=125=static bool\nlib/crypto/chacha20poly1305.c:126:__chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\nlib/crypto/chacha20poly1305.c-127-\t\t\t const u8 *ad, const size_t ad_len,\n--\nlib/crypto/chacha20poly1305.c-172-\nlib/crypto/chacha20poly1305.c:173:bool chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\nlib/crypto/chacha20poly1305.c-174-\t\t\t const u8 *ad, const size_t ad_len,\n--\nlib/crypto/chacha20poly1305.c-188-\tchacha_init(\u0026chacha_state, k, (u8 *)iv);\nlib/crypto/chacha20poly1305.c:189:\tret = __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,\nlib/crypto/chacha20poly1305.c-190-\t\t\t\t\t \u0026chacha_state);\n--\nlib/crypto/chacha20poly1305.c-195-}\nlib/crypto/chacha20poly1305.c:196:EXPORT_SYMBOL(chacha20poly1305_decrypt);\nlib/crypto/chacha20poly1305.c-197-\nlib/crypto/chacha20poly1305.c:198:bool xchacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\nlib/crypto/chacha20poly1305.c-199-\t\t\t const u8 *ad, const size_t ad_len,\n--\nlib/crypto/chacha20poly1305.c-205-\txchacha_init(\u0026chacha_state, key, nonce);\nlib/crypto/chacha20poly1305.c:206:\treturn __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,\nlib/crypto/chacha20poly1305.c-207-\t\t\t\t\t \u0026chacha_state);\nlib/crypto/chacha20poly1305.c-208-}\nlib/crypto/chacha20poly1305.c:209:EXPORT_SYMBOL(xchacha20poly1305_decrypt);\nlib/crypto/chacha20poly1305.c-210-\n--\nlib/crypto/chacha20poly1305.c=345=EXPORT_SYMBOL(chacha20poly1305_encrypt_sg_inplace);\nlib/crypto/chacha20poly1305.c-346-\nlib/crypto/chacha20poly1305.c:347:bool chacha20poly1305_decrypt_sg_inplace(struct scatterlist *src, size_t src_len,\nlib/crypto/chacha20poly1305.c-348-\t\t\t\t\t const u8 *ad, const size_t ad_len,\n--\nlib/crypto/chacha20poly1305.c-358-}\nlib/crypto/chacha20poly1305.c:359:EXPORT_SYMBOL(chacha20poly1305_decrypt_sg_inplace);\nlib/crypto/chacha20poly1305.c-360-\n--\nlib/crypto/tests/chacha20poly1305_kunit.c=8885=static void test_chacha20poly1305(struct kunit *test)\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-8938-\t\tmemset(computed_output, 0, MAXIMUM_TEST_BUFFER_LEN);\nlib/crypto/tests/chacha20poly1305_kunit.c:8939:\t\tret = chacha20poly1305_decrypt(computed_output,\nlib/crypto/tests/chacha20poly1305_kunit.c-8940-\t\t\tchacha20poly1305_dec_vectors[i].input,\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-8961-\t\t\t chacha20poly1305_dec_vectors[i].ilen);\nlib/crypto/tests/chacha20poly1305_kunit.c:8962:\t\tret = chacha20poly1305_decrypt_sg_inplace(sg_src,\nlib/crypto/tests/chacha20poly1305_kunit.c-8963-\t\t\tchacha20poly1305_dec_vectors[i].ilen,\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-8998-\t\tmemset(computed_output, 0, MAXIMUM_TEST_BUFFER_LEN);\nlib/crypto/tests/chacha20poly1305_kunit.c:8999:\t\tret = xchacha20poly1305_decrypt(computed_output,\nlib/crypto/tests/chacha20poly1305_kunit.c-9000-\t\t\t\t\txchacha20poly1305_dec_vectors[i].input,\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-9042-\t\t\t\t\tgoto chunkfail;\nlib/crypto/tests/chacha20poly1305_kunit.c:9043:\t\t\t\tif (!chacha20poly1305_decrypt(computed_output,\nlib/crypto/tests/chacha20poly1305_kunit.c-9044-\t\t\t\t\tinput, total_len, NULL, 0, 0, enc_key001))\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-9049-\t\t\t\t}\nlib/crypto/tests/chacha20poly1305_kunit.c:9050:\t\t\t\tif (!chacha20poly1305_decrypt_sg_inplace(sg_src,\nlib/crypto/tests/chacha20poly1305_kunit.c-9051-\t\t\t\t\ttotal_len, NULL, 0, 0, enc_key001))\n--\nsecurity/keys/big_key.c=227=long big_key_read(const struct key *key, char *buffer, size_t buflen)\n--\nsecurity/keys/big_key.c-259-\nsecurity/keys/big_key.c:260:\t\tret = chacha20poly1305_decrypt(buf, buf, enclen, NULL, 0, 0,\nsecurity/keys/big_key.c-261-\t\t\t\t\t enckey) ? 0 : -EBADMSG;\n"
} |
| 9/2 | 2026/10/04 05:20 | llm | patch-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 9119 output: 31 thoughts: 94 Thoughts: Here's my thought process, as it stands: **Exploring the `chacha20poly1305_decrypt` Usage** Okay, first things first, I need to get a clear picture of where `chacha20poly1305_decrypt` is being used within the system. My initial scan has revealed three call sites. I need to note where they are so I can focus in later. Looks like: * The `drivers/net/wireguard` module is using it for decrypting noise handshake messages and consuming cookies. Interesting, I'll need to remember that. * `security/keys/big_key.c` -- I'll want to investigate how it's integrated within the key management system. * `chacha20poly1305_kunit.c` -- this is probably a unit test, but it still shows potential usage patterns. Now, to see how the kernel config is set up I need to check the Kconfig file for `lib/crypto/chacha20poly1305.c`. That should give me the configuration options related to the implementation. |
| 10/2 | 2026/10/04 05:20 | tool | grepper |
0mArgs:{
"Expression": "chacha20poly1305",
"PathPrefix": "lib/crypto"
}Results: {
"Output": "\nFull output is too long, showing 200 out of 299 lines.\nUse more precise expression if possible.\n\nlib/crypto/Makefile=119=endif # CONFIG_CRYPTO_LIB_CHACHA_ARCH\n--\nlib/crypto/Makefile-122-\nlib/crypto/Makefile:123:obj-$(CONFIG_CRYPTO_LIB_CHACHA20POLY1305)\t+= libchacha20poly1305.o\nlib/crypto/Makefile:124:libchacha20poly1305-y\t\t\t\t+= chacha20poly1305.o\nlib/crypto/Makefile-125-\n--\nlib/crypto/chacha20poly1305.c-10-#include \u003ccrypto/chacha.h\u003e\nlib/crypto/chacha20poly1305.c:11:#include \u003ccrypto/chacha20poly1305.h\u003e\nlib/crypto/chacha20poly1305.c-12-#include \u003ccrypto/poly1305.h\u003e\n--\nlib/crypto/chacha20poly1305.c=54=static void\nlib/crypto/chacha20poly1305.c:55:__chacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,\nlib/crypto/chacha20poly1305.c-56-\t\t\t const u8 *ad, const size_t ad_len,\n--\nlib/crypto/chacha20poly1305.c-88-\nlib/crypto/chacha20poly1305.c:89:void chacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,\nlib/crypto/chacha20poly1305.c-90-\t\t\t const u8 *ad, const size_t ad_len,\n--\nlib/crypto/chacha20poly1305.c-103-\tchacha_init(\u0026chacha_state, k, (u8 *)iv);\nlib/crypto/chacha20poly1305.c:104:\t__chacha20poly1305_encrypt(dst, src, src_len, ad, ad_len,\nlib/crypto/chacha20poly1305.c-105-\t\t\t\t \u0026chacha_state);\n--\nlib/crypto/chacha20poly1305.c-109-}\nlib/crypto/chacha20poly1305.c:110:EXPORT_SYMBOL(chacha20poly1305_encrypt);\nlib/crypto/chacha20poly1305.c-111-\nlib/crypto/chacha20poly1305.c:112:void xchacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,\nlib/crypto/chacha20poly1305.c-113-\t\t\t const u8 *ad, const size_t ad_len,\n--\nlib/crypto/chacha20poly1305.c-119-\txchacha_init(\u0026chacha_state, key, nonce);\nlib/crypto/chacha20poly1305.c:120:\t__chacha20poly1305_encrypt(dst, src, src_len, ad, ad_len,\nlib/crypto/chacha20poly1305.c-121-\t\t\t\t \u0026chacha_state);\nlib/crypto/chacha20poly1305.c-122-}\nlib/crypto/chacha20poly1305.c:123:EXPORT_SYMBOL(xchacha20poly1305_encrypt);\nlib/crypto/chacha20poly1305.c-124-\nlib/crypto/chacha20poly1305.c=125=static bool\nlib/crypto/chacha20poly1305.c:126:__chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\nlib/crypto/chacha20poly1305.c-127-\t\t\t const u8 *ad, const size_t ad_len,\n--\nlib/crypto/chacha20poly1305.c-172-\nlib/crypto/chacha20poly1305.c:173:bool chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\nlib/crypto/chacha20poly1305.c-174-\t\t\t const u8 *ad, const size_t ad_len,\n--\nlib/crypto/chacha20poly1305.c-188-\tchacha_init(\u0026chacha_state, k, (u8 *)iv);\nlib/crypto/chacha20poly1305.c:189:\tret = __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,\nlib/crypto/chacha20poly1305.c-190-\t\t\t\t\t \u0026chacha_state);\n--\nlib/crypto/chacha20poly1305.c-195-}\nlib/crypto/chacha20poly1305.c:196:EXPORT_SYMBOL(chacha20poly1305_decrypt);\nlib/crypto/chacha20poly1305.c-197-\nlib/crypto/chacha20poly1305.c:198:bool xchacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\nlib/crypto/chacha20poly1305.c-199-\t\t\t const u8 *ad, const size_t ad_len,\n--\nlib/crypto/chacha20poly1305.c-205-\txchacha_init(\u0026chacha_state, key, nonce);\nlib/crypto/chacha20poly1305.c:206:\treturn __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,\nlib/crypto/chacha20poly1305.c-207-\t\t\t\t\t \u0026chacha_state);\nlib/crypto/chacha20poly1305.c-208-}\nlib/crypto/chacha20poly1305.c:209:EXPORT_SYMBOL(xchacha20poly1305_decrypt);\nlib/crypto/chacha20poly1305.c-210-\nlib/crypto/chacha20poly1305.c=211=static\nlib/crypto/chacha20poly1305.c:212:bool chacha20poly1305_crypt_sg_inplace(struct scatterlist *src,\nlib/crypto/chacha20poly1305.c-213-\t\t\t\t const size_t src_len,\n--\nlib/crypto/chacha20poly1305.c-336-\nlib/crypto/chacha20poly1305.c:337:bool chacha20poly1305_encrypt_sg_inplace(struct scatterlist *src, size_t src_len,\nlib/crypto/chacha20poly1305.c-338-\t\t\t\t\t const u8 *ad, const size_t ad_len,\n--\nlib/crypto/chacha20poly1305.c-341-{\nlib/crypto/chacha20poly1305.c:342:\treturn chacha20poly1305_crypt_sg_inplace(src, src_len, ad, ad_len,\nlib/crypto/chacha20poly1305.c-343-\t\t\t\t\t\t nonce, key, 1);\nlib/crypto/chacha20poly1305.c-344-}\nlib/crypto/chacha20poly1305.c:345:EXPORT_SYMBOL(chacha20poly1305_encrypt_sg_inplace);\nlib/crypto/chacha20poly1305.c-346-\nlib/crypto/chacha20poly1305.c:347:bool chacha20poly1305_decrypt_sg_inplace(struct scatterlist *src, size_t src_len,\nlib/crypto/chacha20poly1305.c-348-\t\t\t\t\t const u8 *ad, const size_t ad_len,\n--\nlib/crypto/chacha20poly1305.c-354-\nlib/crypto/chacha20poly1305.c:355:\treturn chacha20poly1305_crypt_sg_inplace(src,\nlib/crypto/chacha20poly1305.c-356-\t\t\t\t\t\t src_len - POLY1305_DIGEST_SIZE,\n--\nlib/crypto/chacha20poly1305.c-358-}\nlib/crypto/chacha20poly1305.c:359:EXPORT_SYMBOL(chacha20poly1305_decrypt_sg_inplace);\nlib/crypto/chacha20poly1305.c-360-\n--\nlib/crypto/tests/Makefile=7=obj-$(CONFIG_CRYPTO_LIB_BLAKE2S_KUNIT_TEST) += blake2s_kunit.o\nlib/crypto/tests/Makefile:8:obj-$(CONFIG_CRYPTO_LIB_CHACHA20POLY1305_KUNIT_TEST) += chacha20poly1305_kunit.o\nlib/crypto/tests/Makefile-9-obj-$(CONFIG_CRYPTO_LIB_CURVE25519_KUNIT_TEST) += curve25519_kunit.o\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-5-\nlib/crypto/tests/chacha20poly1305_kunit.c:6:#include \u003ccrypto/chacha20poly1305.h\u003e\nlib/crypto/tests/chacha20poly1305_kunit.c-7-#include \u003ccrypto/chacha.h\u003e\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-15-\nlib/crypto/tests/chacha20poly1305_kunit.c:16:struct chacha20poly1305_testvec {\nlib/crypto/tests/chacha20poly1305_kunit.c-17-\tconst u8 *input, *output, *assoc, *nonce, *key;\n--\nlib/crypto/tests/chacha20poly1305_kunit.c=5923=static const u8 enc_key118[] = {\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-5929-\nlib/crypto/tests/chacha20poly1305_kunit.c:5930:static const struct chacha20poly1305_testvec\nlib/crypto/tests/chacha20poly1305_kunit.c:5931:chacha20poly1305_enc_vectors[] = {\nlib/crypto/tests/chacha20poly1305_kunit.c-5932-\t{ enc_input001, enc_output001, enc_assoc001, enc_nonce001, enc_key001,\n--\nlib/crypto/tests/chacha20poly1305_kunit.c=8593=static const u8 dec_key013[] = {\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-8599-\nlib/crypto/tests/chacha20poly1305_kunit.c:8600:static const struct chacha20poly1305_testvec\nlib/crypto/tests/chacha20poly1305_kunit.c:8601:chacha20poly1305_dec_vectors[] = {\nlib/crypto/tests/chacha20poly1305_kunit.c-8602-\t{ dec_input001, dec_output001, dec_assoc001, dec_nonce001, dec_key001,\n--\nlib/crypto/tests/chacha20poly1305_kunit.c=8714=static const u8 xenc_key001[] = {\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-8720-\nlib/crypto/tests/chacha20poly1305_kunit.c:8721:static const struct chacha20poly1305_testvec\nlib/crypto/tests/chacha20poly1305_kunit.c:8722:xchacha20poly1305_enc_vectors[] = {\nlib/crypto/tests/chacha20poly1305_kunit.c-8723-\t{ xenc_input001, xenc_output001, xenc_assoc001, xenc_nonce001, xenc_key001,\n--\nlib/crypto/tests/chacha20poly1305_kunit.c=8810=static const u8 xdec_key001[] = {\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-8816-\nlib/crypto/tests/chacha20poly1305_kunit.c:8817:static const struct chacha20poly1305_testvec\nlib/crypto/tests/chacha20poly1305_kunit.c:8818:xchacha20poly1305_dec_vectors[] = {\nlib/crypto/tests/chacha20poly1305_kunit.c-8819-\t{ xdec_input001, xdec_output001, xdec_assoc001, xdec_nonce001, xdec_key001,\n--\nlib/crypto/tests/chacha20poly1305_kunit.c=8826=static void\nlib/crypto/tests/chacha20poly1305_kunit.c:8827:chacha20poly1305_encrypt_bignonce(u8 *dst, const u8 *src, const size_t src_len,\nlib/crypto/tests/chacha20poly1305_kunit.c-8828-\t\t\t\t const u8 *ad, const size_t ad_len,\n--\nlib/crypto/tests/chacha20poly1305_kunit.c=8860=static void\nlib/crypto/tests/chacha20poly1305_kunit.c:8861:chacha20poly1305_test_encrypt(struct kunit *test, u8 *dst,\nlib/crypto/tests/chacha20poly1305_kunit.c-8862-\t\t\t const u8 *src, const size_t src_len,\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-8867-\tif (nonce_len == 8)\nlib/crypto/tests/chacha20poly1305_kunit.c:8868:\t\tchacha20poly1305_encrypt(dst, src, src_len, ad, ad_len,\nlib/crypto/tests/chacha20poly1305_kunit.c-8869-\t\t\t\t\t get_unaligned_le64(nonce), key);\nlib/crypto/tests/chacha20poly1305_kunit.c-8870-\telse if (nonce_len == 12)\nlib/crypto/tests/chacha20poly1305_kunit.c:8871:\t\tchacha20poly1305_encrypt_bignonce(dst, src, src_len, ad,\nlib/crypto/tests/chacha20poly1305_kunit.c-8872-\t\t\t\t\t\t ad_len, nonce, key);\n--\nlib/crypto/tests/chacha20poly1305_kunit.c=8878=decryption_success(bool func_ret, bool expect_failure, int memcmp_result)\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-8884-\nlib/crypto/tests/chacha20poly1305_kunit.c:8885:static void test_chacha20poly1305(struct kunit *test)\nlib/crypto/tests/chacha20poly1305_kunit.c-8886-{\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-8895-\nlib/crypto/tests/chacha20poly1305_kunit.c:8896:\tfor (i = 0; i \u003c ARRAY_SIZE(chacha20poly1305_enc_vectors); ++i) {\nlib/crypto/tests/chacha20poly1305_kunit.c-8897-\t\tmemset(computed_output, 0, MAXIMUM_TEST_BUFFER_LEN);\nlib/crypto/tests/chacha20poly1305_kunit.c:8898:\t\tchacha20poly1305_test_encrypt(test, computed_output,\nlib/crypto/tests/chacha20poly1305_kunit.c:8899:\t\t\t\t\tchacha20poly1305_enc_vectors[i].input,\nlib/crypto/tests/chacha20poly1305_kunit.c:8900:\t\t\t\t\tchacha20poly1305_enc_vectors[i].ilen,\nlib/crypto/tests/chacha20poly1305_kunit.c:8901:\t\t\t\t\tchacha20poly1305_enc_vectors[i].assoc,\nlib/crypto/tests/chacha20poly1305_kunit.c:8902:\t\t\t\t\tchacha20poly1305_enc_vectors[i].alen,\nlib/crypto/tests/chacha20poly1305_kunit.c:8903:\t\t\t\t\tchacha20poly1305_enc_vectors[i].nonce,\nlib/crypto/tests/chacha20poly1305_kunit.c:8904:\t\t\t\t\tchacha20poly1305_enc_vectors[i].nlen,\nlib/crypto/tests/chacha20poly1305_kunit.c:8905:\t\t\t\t\tchacha20poly1305_enc_vectors[i].key);\nlib/crypto/tests/chacha20poly1305_kunit.c-8906-\t\tKUNIT_EXPECT_TRUE_MSG(\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-8908-\t\t\tmemcmp(computed_output,\nlib/crypto/tests/chacha20poly1305_kunit.c:8909:\t\t\t chacha20poly1305_enc_vectors[i].output,\nlib/crypto/tests/chacha20poly1305_kunit.c:8910:\t\t\t chacha20poly1305_enc_vectors[i].ilen +\nlib/crypto/tests/chacha20poly1305_kunit.c-8911-\t\t\t\t POLY1305_DIGEST_SIZE) == 0,\nlib/crypto/tests/chacha20poly1305_kunit.c:8912:\t\t\t\"chacha20poly1305 encryption test %zu: FAIL\", i + 1);\nlib/crypto/tests/chacha20poly1305_kunit.c-8913-\t}\nlib/crypto/tests/chacha20poly1305_kunit.c-8914-\nlib/crypto/tests/chacha20poly1305_kunit.c:8915:\tfor (i = 0; i \u003c ARRAY_SIZE(chacha20poly1305_enc_vectors); ++i) {\nlib/crypto/tests/chacha20poly1305_kunit.c:8916:\t\tif (chacha20poly1305_enc_vectors[i].nlen != 8)\nlib/crypto/tests/chacha20poly1305_kunit.c-8917-\t\t\tcontinue;\nlib/crypto/tests/chacha20poly1305_kunit.c:8918:\t\tmemcpy(computed_output, chacha20poly1305_enc_vectors[i].input,\nlib/crypto/tests/chacha20poly1305_kunit.c:8919:\t\t chacha20poly1305_enc_vectors[i].ilen);\nlib/crypto/tests/chacha20poly1305_kunit.c-8920-\t\tsg_init_one(sg_src, computed_output,\nlib/crypto/tests/chacha20poly1305_kunit.c:8921:\t\t\t chacha20poly1305_enc_vectors[i].ilen + POLY1305_DIGEST_SIZE);\nlib/crypto/tests/chacha20poly1305_kunit.c:8922:\t\tret = chacha20poly1305_encrypt_sg_inplace(sg_src,\nlib/crypto/tests/chacha20poly1305_kunit.c:8923:\t\t\tchacha20poly1305_enc_vectors[i].ilen,\nlib/crypto/tests/chacha20poly1305_kunit.c:8924:\t\t\tchacha20poly1305_enc_vectors[i].assoc,\nlib/crypto/tests/chacha20poly1305_kunit.c:8925:\t\t\tchacha20poly1305_enc_vectors[i].alen,\nlib/crypto/tests/chacha20poly1305_kunit.c:8926:\t\t\tget_unaligned_le64(chacha20poly1305_enc_vectors[i].nonce),\nlib/crypto/tests/chacha20poly1305_kunit.c:8927:\t\t\tchacha20poly1305_enc_vectors[i].key);\nlib/crypto/tests/chacha20poly1305_kunit.c-8928-\t\tKUNIT_EXPECT_TRUE_MSG(\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-8930-\t\t\tret \u0026\u0026 memcmp(computed_output,\nlib/crypto/tests/chacha20poly1305_kunit.c:8931:\t\t\t\t chacha20poly1305_enc_vectors[i].output,\nlib/crypto/tests/chacha20poly1305_kunit.c:8932:\t\t\t\t chacha20poly1305_enc_vectors[i].ilen +\nlib/crypto/tests/chacha20poly1305_kunit.c-8933-\t\t\t\t\t POLY1305_DIGEST_SIZE) == 0,\nlib/crypto/tests/chacha20poly1305_kunit.c:8934:\t\t\t\"chacha20poly1305 sg encryption test %zu: FAIL\", i + 1);\nlib/crypto/tests/chacha20poly1305_kunit.c-8935-\t}\nlib/crypto/tests/chacha20poly1305_kunit.c-8936-\nlib/crypto/tests/chacha20poly1305_kunit.c:8937:\tfor (i = 0; i \u003c ARRAY_SIZE(chacha20poly1305_dec_vectors); ++i) {\nlib/crypto/tests/chacha20poly1305_kunit.c-8938-\t\tmemset(computed_output, 0, MAXIMUM_TEST_BUFFER_LEN);\nlib/crypto/tests/chacha20poly1305_kunit.c:8939:\t\tret = chacha20poly1305_decrypt(computed_output,\nlib/crypto/tests/chacha20poly1305_kunit.c:8940:\t\t\tchacha20poly1305_dec_vectors[i].input,\nlib/crypto/tests/chacha20poly1305_kunit.c:8941:\t\t\tchacha20poly1305_dec_vectors[i].ilen,\nlib/crypto/tests/chacha20poly1305_kunit.c:8942:\t\t\tchacha20poly1305_dec_vectors[i].assoc,\nlib/crypto/tests/chacha20poly1305_kunit.c:8943:\t\t\tchacha20poly1305_dec_vectors[i].alen,\nlib/crypto/tests/chacha20poly1305_kunit.c:8944:\t\t\tget_unaligned_le64(chacha20poly1305_dec_vectors[i].nonce),\nlib/crypto/tests/chacha20poly1305_kunit.c:8945:\t\t\tchacha20poly1305_dec_vectors[i].key);\nlib/crypto/tests/chacha20poly1305_kunit.c-8946-\t\tKUNIT_EXPECT_TRUE_MSG(\n--\nlib/crypto/tests/chacha20poly1305_kunit.c-8948-\t\t\tdecryption_success(\nlib/crypto/tests/chacha20poly1305_kunit.c:8949:\t\t\t\tret, chacha20poly1305_dec_vectors[i].failure,\n\n"
} |
| 11/2 | 2026/10/04 05:20 | llm | patch-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 15872 output: 20 thoughts: 16 Thoughts: Okay, here's my take on those thoughts, tailored for an expert audience: **Analyzing the Commit Log: A Methodical Approach** Alright, before I dive in headfirst, let's take a beat. My first instinct is always to check the commit log. I need to understand the 'why' behind the change. Diving straight into the code without understanding the context is a recipe for wasted time and potential mistakes, especially on a codebase like this. The commit message – that's the key. That's where the original developer hopefully laid out their intention, what they were trying to achieve, and maybe even the specific problem they were addressing. A well-written commit message is a goldmine. It's the first place I go to grasp the overall architecture and intent. So, let me pull up the git log and see what we've got. Hopefully, it's insightful. If not, I may need to use other methods. |
| 12/2 | 2026/10/04 05:20 | tool | grepper |
0mArgs:{
"Expression": "chacha_zeroize_state"
}Results: {
"Output": "drivers/char/random.c=386=static void _get_random_bytes(void *buf, size_t len)\n--\ndrivers/char/random.c-414-\ndrivers/char/random.c:415:\tchacha_zeroize_state(\u0026chacha_state);\ndrivers/char/random.c-416-}\n--\ndrivers/char/random.c=431=static ssize_t get_random_bytes_user(struct iov_iter *iter)\n--\ndrivers/char/random.c-476-out_zero_chacha:\ndrivers/char/random.c:477:\tchacha_zeroize_state(\u0026chacha_state);\ndrivers/char/random.c-478-\treturn ret ? ret : -EFAULT;\n--\ninclude/crypto/chacha.h=91=static inline void chacha20_crypt(struct chacha_state *state,\n--\ninclude/crypto/chacha.h-96-\ninclude/crypto/chacha.h:97:static inline void chacha_zeroize_state(struct chacha_state *state)\ninclude/crypto/chacha.h-98-{\n--\nlib/crypto/chacha-block-generic.c=77=void chacha_block_generic(struct chacha_state *state,\n--\nlib/crypto/chacha-block-generic.c-90-\nlib/crypto/chacha-block-generic.c:91:\tchacha_zeroize_state(\u0026permuted_state);\nlib/crypto/chacha-block-generic.c-92-}\n--\nlib/crypto/chacha-block-generic.c=106=void hchacha_block_generic(const struct chacha_state *state,\n--\nlib/crypto/chacha-block-generic.c-115-\nlib/crypto/chacha-block-generic.c:116:\tchacha_zeroize_state(\u0026permuted_state);\nlib/crypto/chacha-block-generic.c-117-}\n--\nlib/crypto/chacha20poly1305.c=55=__chacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,\n--\nlib/crypto/chacha20poly1305.c-84-\nlib/crypto/chacha20poly1305.c:85:\tchacha_zeroize_state(chacha_state);\nlib/crypto/chacha20poly1305.c-86-\tmemzero_explicit(\u0026b, sizeof(b));\n--\nlib/crypto/chacha20poly1305.c=126=__chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\n--\nlib/crypto/chacha20poly1305.c-140-\tif (unlikely(src_len \u003c POLY1305_DIGEST_SIZE)) {\nlib/crypto/chacha20poly1305.c:141:\t\tchacha_zeroize_state(chacha_state);\nlib/crypto/chacha20poly1305.c-142-\t\treturn false;\n--\nlib/crypto/chacha20poly1305.c-168-\nlib/crypto/chacha20poly1305.c:169:\tchacha_zeroize_state(chacha_state);\nlib/crypto/chacha20poly1305.c-170-\treturn !ret;\n--\nlib/crypto/chacha20poly1305.c=212=bool chacha20poly1305_crypt_sg_inplace(struct scatterlist *src,\n--\nlib/crypto/chacha20poly1305.c-330-\nlib/crypto/chacha20poly1305.c:331:\tchacha_zeroize_state(\u0026chacha_state);\nlib/crypto/chacha20poly1305.c-332-\tmemzero_explicit(\u0026b, sizeof(b));\n"
} |
| 13/2 | 2026/10/04 05:20 | llm | patch-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 17092 output: 29 thoughts: 2627 Thoughts: **Worth Fuzzing Decision: YES** Okay, let's break this down. First, I noticed this code modifies the `__chacha20poly1305_decrypt` function, specifically how the ChaCha20 state is zeroized. Initially, the zeroization was handled differently depending on the calling function, but this commit consolidates it within the core decrypt function. My initial thought was to quickly assess reachability. Where are `chacha20poly1305_decrypt` and `xchacha20poly1305_decrypt` called? I know Syzkaller is my primary tool for this. I found two significant call sites: WireGuard and the big key management system. WireGuard, in `drivers/net/wireguard`, uses both decrypt functions for its core operations, and the kernel documentation says WireGuard is fuzzed by syzkaller. The big key subsystem, specifically `security/keys/big_key.c`, also leverages `chacha20poly1305_decrypt`. I know Syzkaller has coverage for adding keys and interacting with keyctl which is crucial to trigger the related functions. Now, let's analyze the patch's impact. The key change is moving `chacha_zeroize_state(chacha_state)` within the core decryption function. This alters how the state is cleaned up after decryption and what the code does when `src_len < POLY1305_DIGEST_SIZE`. This is not just a cosmetic change; it's a refactoring that *changes* the state management logic. Does this meet the fuzzing guidelines? Let's consult them carefully, and, because it's a refactoring, I won't assume it's safe. It specifically states "Do NOT blindly trust "NO FUNCTIONAL CHANGE" (NFCI) or "REFACTORING" claims. If reachable executable code is modified or refactored, it MUST be fuzzed." This commit clearly modifies executable code within core libraries, specifically in the context of encryption and decryption. Looking at the "negative criteria", I see that *none* of those apply: this is part of the kernel, it *is* executable in standard environments, and this is *not* a non-functional change, it affects program flow and data structure management. The guidelines state, "Return WorthFuzzing=true whenever the patch touches reachable executable code". I will now check Kconfig files to ensure this module can be enabled. |
| 14/2 | 2026/10/04 05:20 | tool | grepper |
0mArgs:{
"Expression": "CRYPTO_LIB_CHACHA20POLY1305"
}Results: {
"Output": "drivers/net/Kconfig=74=config WIREGUARD\n--\ndrivers/net/Kconfig-79-\tselect CRYPTO_LIB_CURVE25519\ndrivers/net/Kconfig:80:\tselect CRYPTO_LIB_CHACHA20POLY1305\ndrivers/net/Kconfig-81-\tselect CRYPTO_LIB_UTILS\n--\nlib/crypto/.kunitconfig=9=CONFIG_CRYPTO_LIB_BLAKE2S_KUNIT_TEST=y\nlib/crypto/.kunitconfig:10:CONFIG_CRYPTO_LIB_CHACHA20POLY1305_KUNIT_TEST=y\nlib/crypto/.kunitconfig-11-CONFIG_CRYPTO_LIB_CURVE25519_KUNIT_TEST=y\n--\nlib/crypto/Kconfig=216=config CRYPTO_LIB_POLY1305_RSIZE\n--\nlib/crypto/Kconfig-222-\nlib/crypto/Kconfig:223:config CRYPTO_LIB_CHACHA20POLY1305\nlib/crypto/Kconfig-224-\ttristate\n--\nlib/crypto/Makefile=119=endif # CONFIG_CRYPTO_LIB_CHACHA_ARCH\n--\nlib/crypto/Makefile-122-\nlib/crypto/Makefile:123:obj-$(CONFIG_CRYPTO_LIB_CHACHA20POLY1305)\t+= libchacha20poly1305.o\nlib/crypto/Makefile-124-libchacha20poly1305-y\t\t\t\t+= chacha20poly1305.o\n--\nlib/crypto/tests/Kconfig=38=config CRYPTO_LIB_BLAKE2S_KUNIT_TEST\n--\nlib/crypto/tests/Kconfig-47-\nlib/crypto/tests/Kconfig:48:config CRYPTO_LIB_CHACHA20POLY1305_KUNIT_TEST\nlib/crypto/tests/Kconfig-49-\ttristate \"KUnit tests for ChaCha20Poly1305\" if !KUNIT_ALL_TESTS\nlib/crypto/tests/Kconfig:50:\tdepends on KUNIT \u0026\u0026 CRYPTO_LIB_CHACHA20POLY1305\nlib/crypto/tests/Kconfig-51-\tdefault KUNIT_ALL_TESTS\n--\nlib/crypto/tests/Kconfig=162=config CRYPTO_LIB_ENABLE_ALL_FOR_KUNIT\n--\nlib/crypto/tests/Kconfig-172-\tselect CRYPTO_LIB_BLAKE2B\nlib/crypto/tests/Kconfig:173:\tselect CRYPTO_LIB_CHACHA20POLY1305\nlib/crypto/tests/Kconfig-174-\tselect CRYPTO_LIB_CURVE25519\n--\nlib/crypto/tests/Makefile=7=obj-$(CONFIG_CRYPTO_LIB_BLAKE2S_KUNIT_TEST) += blake2s_kunit.o\nlib/crypto/tests/Makefile:8:obj-$(CONFIG_CRYPTO_LIB_CHACHA20POLY1305_KUNIT_TEST) += chacha20poly1305_kunit.o\nlib/crypto/tests/Makefile-9-obj-$(CONFIG_CRYPTO_LIB_CURVE25519_KUNIT_TEST) += curve25519_kunit.o\n--\nsecurity/keys/Kconfig=59=config BIG_KEYS\n--\nsecurity/keys/Kconfig-61-\tdepends on TMPFS\nsecurity/keys/Kconfig:62:\tselect CRYPTO_LIB_CHACHA20POLY1305\nsecurity/keys/Kconfig-63-\thelp\n"
} |
| 15/2 | 2026/10/04 05:20 | llm | patch-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 21186 output: 34 thoughts: 19 Thoughts: Here's my take on those thoughts: **Navigating the Kconfig Labyrinth** Okay, so I'm thinking, let's zero in on a specific area within the cryptographic configuration. My mental map immediately goes to `lib/crypto/Kconfig`, and I'm targeting around line 223. This probably means I'm looking for a particular option, a dependency, or a conditional statement related to a specific cryptographic primitive or feature. The line number is a good starting point to locate exactly what I need. |
| 16/2 | 2026/10/04 05:20 | tool | read-file |
0mArgs:{
"File": "lib/crypto/Kconfig",
"FirstLine": 220,
"LineCount": 20
}Results: {
"Contents": " 220:\t\tdefault 9 if ARM || ARM64\n 221:\t\tdefault 1\n 222:\t\n 223:\tconfig CRYPTO_LIB_CHACHA20POLY1305\n 224:\t\ttristate\n 225:\t\tselect CRYPTO_LIB_CHACHA\n 226:\t\tselect CRYPTO_LIB_POLY1305\n 227:\t\tselect CRYPTO_LIB_UTILS\n 228:\t\n 229:\tconfig CRYPTO_LIB_SHA1\n 230:\t\ttristate\n 231:\t\thelp\n 232:\t\t The SHA-1 and HMAC-SHA1 library functions. Select this if your module\n 233:\t\t uses any of the functions from \u003ccrypto/sha1.h\u003e.\n 234:\t\n 235:\tconfig CRYPTO_LIB_SHA1_ARCH\n 236:\t\tbool\n 237:\t\tdepends on CRYPTO_LIB_SHA1 \u0026\u0026 !UML\n 238:\t\tdefault y if ARM\n 239:\t\tdefault y if ARM64\n"
} |
| 17/2 | 2026/10/04 05:20 | llm | patch-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 21642 output: 33 thoughts: 73 Thoughts: Here's my analysis of this situation: **Investigating a Missing Configuration Prompt** Alright, so `CRYPTO_LIB_CHACHA20POLY1305` is being selected, but it lacks a direct prompt. That's a bit odd. My initial suspicion, as indicated, is that it's being pulled in indirectly through a dependency. The hint here is that the selections are either `WIREGUARD`, `BIG_KEYS`, or potentially `CRYPTO_LIB_ENABLE_ALL_FOR_KUNIT`. That makes sense; if it's being dragged in by a more specific feature, or potentially a testing configuration, it wouldn't need its own top-level prompt. Now, the next logical step is to check where `WIREGUARD` is defined, and see which paths lead to it being configured. I'll need to dig into the `drivers/net/Kconfig` file and trace the dependencies from there. This should clarify the selection path and why this particular cryptographic library is being enabled. |
| 18/2 | 2026/10/04 05:20 | tool | read-file |
0mArgs:{
"File": "drivers/net/Kconfig",
"FirstLine": 70,
"LineCount": 25
}Results: {
"Contents": " 70:\t\n 71:\t\t To compile this driver as a module, choose M here: the module\n 72:\t\t will be called dummy.\n 73:\t\n 74:\tconfig WIREGUARD\n 75:\t\ttristate \"WireGuard secure network tunnel\"\n 76:\t\tdepends on NET \u0026\u0026 INET\n 77:\t\tselect NET_UDP_TUNNEL\n 78:\t\tselect DST_CACHE\n 79:\t\tselect CRYPTO_LIB_CURVE25519\n 80:\t\tselect CRYPTO_LIB_CHACHA20POLY1305\n 81:\t\tselect CRYPTO_LIB_UTILS\n 82:\t\thelp\n 83:\t\t WireGuard is a secure, fast, and easy to use replacement for IPSec\n 84:\t\t that uses modern cryptography and clever networking tricks. It's\n 85:\t\t designed to be fairly general purpose and abstract enough to fit most\n 86:\t\t use cases, while at the same time remaining extremely simple to\n 87:\t\t configure. See www.wireguard.com for more info.\n 88:\t\n 89:\t\t It's safe to say Y or M here, as the driver is very lightweight and\n 90:\t\t is only in use when an administrator chooses to add an interface.\n 91:\t\n 92:\tconfig WIREGUARD_DEBUG\n 93:\t\tbool \"Debugging checks and verbose messages\"\n 94:\t\tdepends on WIREGUARD\n"
} |
| 19/2 | 2026/10/04 05:20 | llm | patch-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 22344 output: 33 thoughts: 15 Thoughts: Okay, here's my interpretation of that seemingly simple text, presented as my internal thought process, assuming I'm an expert in the field: **Internal Monologue on Key Configuration** Right, so "And `BIG_KEYS` in `security/keys/Kconfig`"... that's intriguing. My initial thought is this likely refers to a configuration option within a kernel build system, specifically related to the security subsystem and key management. The use of all caps, `BIG_KEYS`, immediately flags it as something potentially significant, probably a feature that can be enabled or disabled during kernel compilation. My mind starts to race through the implications. "Big keys" could signify a number of things. Are we talking about support for larger cryptographic keys, perhaps exceeding the standard sizes for algorithms like RSA or ECC? This could be driven by a need for increased security against modern cryptanalytic attacks. Perhaps it deals with hardware-backed keys and key storage? Or is it more oriented toward features like key attestation? I should probably check the commit history, or related documentation, to understand *why* this feature has been added, and what problem it's designed to solve. The "Kconfig" location is a dead giveaway. That means we're dealing with the core kernel configuration system. This is where options like "Enable filesystem encryption" or "Support TPM hardware" are controlled. So, `BIG_KEYS` is likely a top-level option that controls the inclusion of a whole suite of functionality, or perhaps a prerequisite option for another security configuration. This is definitely something I need to understand, especially if I'm deploying or auditing systems that rely on the kernel's key management infrastructure. I'm now thinking about the potential security implications. If these keys are "big," it could mean a performance overhead, especially on resource-constrained systems. I'll need to consider how this would affect the overall boot time, memory usage, and potentially the cryptographic throughput. I'm also considering the attack surface – larger key sizes can introduce new attack vectors or increase complexity. It also forces me to consider the implications of key storage on the system. I'll need to dig into the relevant Kconfig file and maybe the source code to see what dependencies are involved, what algorithms are supported, and any potential caveats. This is probably going to dictate significant security design choices. It is another piece of my daily security puzzle. |
| 20/2 | 2026/10/04 05:20 | tool | read-file |
0mArgs:{
"File": "security/keys/Kconfig",
"FirstLine": 55,
"LineCount": 25
}Results: {
"Contents": " 55:\t\n 56:\t\t Keyrings are created and added into the register upon demand and get\n 57:\t\t removed if they expire (a default timeout is set upon creation).\n 58:\t\n 59:\tconfig BIG_KEYS\n 60:\t\tbool \"Large payload keys\"\n 61:\t\tdepends on TMPFS\n 62:\t\tselect CRYPTO_LIB_CHACHA20POLY1305\n 63:\t\thelp\n 64:\t\t This option provides support for holding large keys within the kernel\n 65:\t\t (for example Kerberos ticket caches). The data may be stored out to\n 66:\t\t swapspace by tmpfs.\n 67:\t\n 68:\t\t If you are unsure as to whether this is required, answer N.\n 69:\t\n 70:\tconfig TRUSTED_KEYS\n 71:\t\ttristate \"TRUSTED KEYS\"\n 72:\t\thelp\n 73:\t\t This option provides support for creating, sealing, and unsealing\n 74:\t\t keys in the kernel. Trusted keys are random number symmetric keys,\n 75:\t\t generated and sealed by a trust source selected at kernel boot-time.\n 76:\t\t Userspace will only ever see encrypted blobs.\n 77:\t\n 78:\t\t If you are unsure as to whether this is required, answer N.\n 79:\t\n"
} |
| 21/2 | 2026/10/04 05:20 | llm | patch-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 23245 output: 199 thoughts: 1334 Thoughts: **Triage Analysis: ChaCha20Poly1305 Decryption Enhancement** Okay, let's break this down. From the configuration perspective, we have `WIREGUARD` and `BIG_KEYS` selecting `CRYPTO_LIB_CHACHA20POLY1305`, and the latter can also be directly enabled. Good. This confirms the code is enabled, but what are the functions of interest? The diff identifies modifications to `__chacha20poly1305_decrypt` (static) and `chacha20poly1305_decrypt` (exported). The static nature of `__chacha20poly1305_decrypt` gives me pause - is it inlined? Checking the code, both `chacha20poly1305_decrypt` and `xchacha20poly1305_decrypt` call it. I know I need to be careful with static inline functions regarding fuzzing. Time to reference Section 4. Right, so the guidance is to focus on feature-specific callers and entrypoints, avoiding ubiquitous lifecycle functions, and it confirms syzkaller can handle static symbols if they are present. So, let's enumerate the symbols: `chacha20poly1305_decrypt`, `xchacha20poly1305_decrypt`, and `__chacha20poly1305_decrypt` (even though it's static) are all present in `lib/crypto/chacha20poly1305.c`. Now, who calls these functions? `wg_cookie_message_consume` calls `xchacha20poly1305_decrypt`, and `message_decrypt` calls `chacha20poly1305_decrypt` in WireGuard. In Big Keys, `big_key_read` calls `chacha20poly1305_decrypt`. That's important for the `FocusSymbols`. Therefore, the `FocusSymbols` for fuzzing should include "chacha20poly1305_decrypt", "xchacha20poly1305_decrypt", and "__chacha20poly1305_decrypt". I need to confirm there are no other relevant callers. Specifically, `chacha20poly1305_crypt_sg_inplace` or `chacha20poly1305_decrypt_sg_inplace` were *not* modified, which means they are not a target here. Good to check. The `EnableConfigs` should be `CRYPTO_LIB_CHACHA20POLY1305`, `WIREGUARD`, and `BIG_KEYS`. `CRYPTO_LIB_CHACHA20POLY1305` is tristate and it's not directly selectable in menuconfig, therefore, `WIREGUARD` and `BIG_KEYS` are required. Now, let's run through the triage criteria again: 1. **Reachable?** Yes, the functions are part of WireGuard and BIG_KEYS, both of which are standard kernel components and fuzzed in syzkaller. 2. **Non-executable/documentation/userspace/vendor hardware/teardown?** No, it's core cryptographic library code. 3. **Change?** This patch ensures proper zeroization of the ChaCha state in the error paths and across all callers of the decryption functions. It is about a security hardening measure. 4. **WorthFuzzing?** Yes. 5. **FocusSymbols:** "chacha20poly1305_decrypt", "xchacha20poly1305_decrypt", "__chacha20poly1305_decrypt". 6. **EnableConfigs:** `CRYPTO_LIB_CHACHA20POLY1305`, `WIREGUARD`, and `BIG_KEYS`. Everything aligns, and it's a security-relevant change, which needs to be fuzz-tested. Alright, time to `set-results`. |
| 22/2 | 2026/10/04 05:21 | tool | set-results |
0mArgs:{
"EnableConfigs": [
"CRYPTO_LIB_CHACHA20POLY1305",
"WIREGUARD",
"BIG_KEYS"
],
"FocusSymbols": [
"chacha20poly1305_decrypt",
"xchacha20poly1305_decrypt",
"__chacha20poly1305_decrypt"
],
"Reasoning": "The patch modifies executable crypto code in lib/crypto/chacha20poly1305.c by moving chacha_zeroize_state() into __chacha20poly1305_decrypt(), ensuring sensitive cipher state is cleared on early return and for all callers including xchacha20poly1305_decrypt(). The modified routines are reachable via virtual network devices (WireGuard) and keyrings (big_key), making it suitable for fuzzing.",
"WorthFuzzing": true
}Results: {
"EnableConfigs": [
"CRYPTO_LIB_CHACHA20POLY1305",
"WIREGUARD",
"BIG_KEYS"
],
"FocusSymbols": [
"chacha20poly1305_decrypt",
"xchacha20poly1305_decrypt",
"__chacha20poly1305_decrypt"
],
"Reasoning": "The patch modifies executable crypto code in lib/crypto/chacha20poly1305.c by moving chacha_zeroize_state() into __chacha20poly1305_decrypt(), ensuring sensitive cipher state is cleared on early return and for all callers including xchacha20poly1305_decrypt(). The modified routines are reachable via virtual network devices (WireGuard) and keyrings (big_key), making it suitable for fuzzing.",
"WorthFuzzing": true
} |
| 23/1 | 2026/10/04 05:21 | action | If |
0mArgs:{
"WorthFuzzing": true
}Results: null |
| 24/2 | 2026/10/04 05:21 | agent | kmsan-evaluator |
0mModel:core Args: null Results: {
"KMSANReasoning": "The patch moves the zeroization of `chacha_state` via `chacha_zeroize_state()` into `__chacha20poly1305_decrypt()`, ensuring the ChaCha state is wiped on all exit paths (including the early-return path when `src_len \u003c POLY1305_DIGEST_SIZE`) and for all callers (including `xchacha20poly1305_decrypt()`).\n\nThis is a cryptographic hygiene change that only explicitly zeroes out memory buffers before returning. It does not introduce, read, branch on, or leak uninitialized memory to user space, nor does it alter memory allocation or buffer bounds. Therefore, KMSAN is not applicable.",
"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 fba883ec5c7801fa6bfe973fa73cb8647f14d638
Author: syz-cluster <triage@syzkaller.com>
Date: Sun Oct 4 05:19:52 2026 +0000
syz-cluster: applied patch under review
diff --git a/lib/crypto/chacha20poly1305.c b/lib/crypto/chacha20poly1305.c
index ea42a28f4ff7d..80904321458b4 100644
--- a/lib/crypto/chacha20poly1305.c
+++ b/lib/crypto/chacha20poly1305.c
@@ -137,8 +137,10 @@ __chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
__le64 lens[2];
} b;
- if (unlikely(src_len < POLY1305_DIGEST_SIZE))
+ if (unlikely(src_len < POLY1305_DIGEST_SIZE)) {
+ chacha_zeroize_state(chacha_state);
return false;
+ }
chacha20_crypt(chacha_state, b.block0, pad0, sizeof(b.block0));
poly1305_init(&poly1305_state, b.block0);
@@ -164,6 +166,7 @@ __chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
memzero_explicit(&b, sizeof(b));
+ chacha_zeroize_state(chacha_state);
return !ret;
}
@@ -186,7 +189,6 @@ bool chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
ret = __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,
&chacha_state);
- chacha_zeroize_state(&chacha_state);
memzero_explicit(iv, sizeof(iv));
memzero_explicit(k, sizeof(k));
return ret;
|
| 25/3 | 2026/10/04 05:21 | llm | kmsan-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 2392 output: 42 thoughts: 647 Thoughts: **Reviewing the Patch for KMSAN Fuzzing Necessity** Okay, so I've got a patch here for `lib/crypto/chacha20poly1305.c`, and the task is to determine if it warrants a dedicated KMSAN fuzzing session. This is pretty standard kernel maintenance, part of my usual QA and bug detection workflow, nothing unusual. Based on the request analysis, it's a benign or even nonexistent severity issue and safe to proceed, no red flags. Now, let's take a look at this patch itself. Hmm, it seems like the core change is adding a couple of `chacha_zeroize_state()` calls. Specifically, it's adding these calls in a couple of places within the `__chacha20poly1305_decrypt` function, and a similar cleanup is performed in the wrapper `chacha20poly1305_decrypt` which calls the former. This is good to see; it looks like we are explicitly zeroing out sensitive state data in the case of a failed decryption, and at the end of the `decrypt` function. The original function didn't do this. I'm assuming we're dealing with cryptographic key material here. I'm thinking, this is a reasonable change for defensive security. It's about protecting against potential information leakage from the key if something goes wrong. This isn't likely to introduce any new memory safety issues that KMSAN would specifically target. KMSAN is great for catching use-after-free and other memory-related errors, but this looks more like a standard cleanup and security hardening fix. It doesn't modify the core algorithm, it's just adding cleanup after the operation. So, while any kernel change can *potentially* benefit from fuzzing, this patch *specifically* doesn't seem to be introducing new code that is highly susceptible to memory errors. I'd lean towards saying we *don't* need a dedicated KMSAN session for this one. I'll make a note of this for the reviewer, just to ensure that the change is functionally sound, but I don't see any obvious KMSAN implications at first glance. I'll also do a quick `read-file` or `grepper` search to confirm there are no obvious missed details in my brief look, to be completely sure. |
| 26/3 | 2026/10/04 05:21 | tool | read-file |
0mArgs:{
"File": "lib/crypto/chacha20poly1305.c",
"FirstLine": 120,
"LineCount": 85
}Results: {
"Contents": " 120:\t\t__chacha20poly1305_encrypt(dst, src, src_len, ad, ad_len,\n 121:\t\t\t\t\t \u0026chacha_state);\n 122:\t}\n 123:\tEXPORT_SYMBOL(xchacha20poly1305_encrypt);\n 124:\t\n 125:\tstatic bool\n 126:\t__chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\n 127:\t\t\t\t const u8 *ad, const size_t ad_len,\n 128:\t\t\t\t struct chacha_state *chacha_state)\n 129:\t{\n 130:\t\tconst u8 *pad0 = page_address(ZERO_PAGE(0));\n 131:\t\tstruct poly1305_desc_ctx poly1305_state;\n 132:\t\tsize_t dst_len;\n 133:\t\tint ret;\n 134:\t\tunion {\n 135:\t\t\tu8 block0[POLY1305_KEY_SIZE];\n 136:\t\t\tu8 mac[POLY1305_DIGEST_SIZE];\n 137:\t\t\t__le64 lens[2];\n 138:\t\t} b;\n 139:\t\n 140:\t\tif (unlikely(src_len \u003c POLY1305_DIGEST_SIZE)) {\n 141:\t\t\tchacha_zeroize_state(chacha_state);\n 142:\t\t\treturn false;\n 143:\t\t}\n 144:\t\n 145:\t\tchacha20_crypt(chacha_state, b.block0, pad0, sizeof(b.block0));\n 146:\t\tpoly1305_init(\u0026poly1305_state, b.block0);\n 147:\t\n 148:\t\tpoly1305_update(\u0026poly1305_state, ad, ad_len);\n 149:\t\tif (ad_len \u0026 0xf)\n 150:\t\t\tpoly1305_update(\u0026poly1305_state, pad0, 0x10 - (ad_len \u0026 0xf));\n 151:\t\n 152:\t\tdst_len = src_len - POLY1305_DIGEST_SIZE;\n 153:\t\tpoly1305_update(\u0026poly1305_state, src, dst_len);\n 154:\t\tif (dst_len \u0026 0xf)\n 155:\t\t\tpoly1305_update(\u0026poly1305_state, pad0, 0x10 - (dst_len \u0026 0xf));\n 156:\t\n 157:\t\tb.lens[0] = cpu_to_le64(ad_len);\n 158:\t\tb.lens[1] = cpu_to_le64(dst_len);\n 159:\t\tpoly1305_update(\u0026poly1305_state, (u8 *)b.lens, sizeof(b.lens));\n 160:\t\n 161:\t\tpoly1305_final(\u0026poly1305_state, b.mac);\n 162:\t\n 163:\t\tret = crypto_memneq(b.mac, src + dst_len, POLY1305_DIGEST_SIZE);\n 164:\t\tif (likely(!ret))\n 165:\t\t\tchacha20_crypt(chacha_state, dst, src, dst_len);\n 166:\t\n 167:\t\tmemzero_explicit(\u0026b, sizeof(b));\n 168:\t\n 169:\t\tchacha_zeroize_state(chacha_state);\n 170:\t\treturn !ret;\n 171:\t}\n 172:\t\n 173:\tbool chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\n 174:\t\t\t\t const u8 *ad, const size_t ad_len,\n 175:\t\t\t\t const u64 nonce,\n 176:\t\t\t\t const u8 key[at_least CHACHA20POLY1305_KEY_SIZE])\n 177:\t{\n 178:\t\tstruct chacha_state chacha_state;\n 179:\t\tu32 k[CHACHA_KEY_WORDS];\n 180:\t\t__le64 iv[2];\n 181:\t\tbool ret;\n 182:\t\n 183:\t\tchacha_load_key(k, key);\n 184:\t\n 185:\t\tiv[0] = 0;\n 186:\t\tiv[1] = cpu_to_le64(nonce);\n 187:\t\n 188:\t\tchacha_init(\u0026chacha_state, k, (u8 *)iv);\n 189:\t\tret = __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,\n 190:\t\t\t\t\t\t \u0026chacha_state);\n 191:\t\n 192:\t\tmemzero_explicit(iv, sizeof(iv));\n 193:\t\tmemzero_explicit(k, sizeof(k));\n 194:\t\treturn ret;\n 195:\t}\n 196:\tEXPORT_SYMBOL(chacha20poly1305_decrypt);\n 197:\t\n 198:\tbool xchacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\n 199:\t\t\t\t const u8 *ad, const size_t ad_len,\n 200:\t\t\t\t const u8 nonce[at_least XCHACHA20POLY1305_NONCE_SIZE],\n 201:\t\t\t\t const u8 key[at_least CHACHA20POLY1305_KEY_SIZE])\n 202:\t{\n 203:\t\tstruct chacha_state chacha_state;\n 204:\t\n"
} |
| 27/3 | 2026/10/04 05:21 | llm | kmsan-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 5121 output: 42 thoughts: 50 Thoughts: Here's my take on the thought process: **Diving into the Implementation Details** Okay, so I need to understand how this `xchacha20poly1305_decrypt` function is actually working. I'm already pretty familiar with the overall cryptographic concepts, but I want to see the nitty-gritty. Let's not just assume; I need to verify how `xchacha20poly1305_decrypt` within `lib/crypto/chacha20poly1305.c` specifically leverages the underlying building blocks. My intuition tells me that lines 200-220 are a good place to start, so I'll zero in on that section of code to see what's happening. I expect to see the key derivation, nonce handling, and the actual AEAD decryption process being performed there. It's time to get a good handle on its execution flow. |
| 28/3 | 2026/10/04 05:21 | tool | read-file |
0mArgs:{
"File": "lib/crypto/chacha20poly1305.c",
"FirstLine": 200,
"LineCount": 40
}Results: {
"Contents": " 200:\t\t\t\t const u8 nonce[at_least XCHACHA20POLY1305_NONCE_SIZE],\n 201:\t\t\t\t const u8 key[at_least CHACHA20POLY1305_KEY_SIZE])\n 202:\t{\n 203:\t\tstruct chacha_state chacha_state;\n 204:\t\n 205:\t\txchacha_init(\u0026chacha_state, key, nonce);\n 206:\t\treturn __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,\n 207:\t\t\t\t\t\t \u0026chacha_state);\n 208:\t}\n 209:\tEXPORT_SYMBOL(xchacha20poly1305_decrypt);\n 210:\t\n 211:\tstatic\n 212:\tbool chacha20poly1305_crypt_sg_inplace(struct scatterlist *src,\n 213:\t\t\t\t\t const size_t src_len,\n 214:\t\t\t\t\t const u8 *ad, const size_t ad_len,\n 215:\t\t\t\t\t const u64 nonce,\n 216:\t\t\t\t\t const u8 key[at_least CHACHA20POLY1305_KEY_SIZE],\n 217:\t\t\t\t\t int encrypt)\n 218:\t{\n 219:\t\tconst u8 *pad0 = page_address(ZERO_PAGE(0));\n 220:\t\tstruct poly1305_desc_ctx poly1305_state;\n 221:\t\tstruct chacha_state chacha_state;\n 222:\t\tstruct sg_mapping_iter miter;\n 223:\t\tsize_t partial = 0;\n 224:\t\tunsigned int flags;\n 225:\t\tbool ret = true;\n 226:\t\tint sl;\n 227:\t\tunion {\n 228:\t\t\tstruct {\n 229:\t\t\t\tu32 k[CHACHA_KEY_WORDS];\n 230:\t\t\t\t__le64 iv[2];\n 231:\t\t\t};\n 232:\t\t\tu8 block0[POLY1305_KEY_SIZE];\n 233:\t\t\tu8 chacha_stream[CHACHA_BLOCK_SIZE];\n 234:\t\t\tstruct {\n 235:\t\t\t\tu8 mac[2][POLY1305_DIGEST_SIZE];\n 236:\t\t\t};\n 237:\t\t\t__le64 lens[2];\n 238:\t\t} b __aligned(16);\n 239:\t\n"
} |
| 29/3 | 2026/10/04 05:21 | llm | kmsan-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 6076 output: 20 thoughts: 599 Thoughts: **Analyzing the Crypto Cleanup in `xchacha20poly1305_decrypt`** Okay, let's break this down. I'm looking at the changes in `xchacha20poly1305_decrypt` and I see a significant difference compared to the original `chacha20poly1305_decrypt`. Previously, the code would zeroize the ChaCha state after decryption, as well as the key and IV. But in the new implementation of `xchacha20poly1305_decrypt` it did *not* zeroize the ChaCha state. The thing is, inside `__chacha20poly1305_decrypt`, there's an early return if the source length is smaller than `POLY1305_DIGEST_SIZE` – it would return `false` without zeroing. By moving `chacha_zeroize_state` into `__chacha20poly1305_decrypt`, we make sure the ChaCha state is zeroed *every* time the function exits, regardless of the path. That's a good move for security; it ensures that the cryptographic state is cleared from the stack. Now, my concern, as always, is whether this introduces any vulnerabilities. Specifically, uninitialized memory risks. Let's run through the possibilities: * **Uninitialized memory read or copied to user space?** No, the zeroization is a *write* operation, it doesn't involve any reads of potentially uninitialized memory. * **Conditional logic or branching depending on uninitialized variables?** No, the logic relies on the length of the input, which is properly initialized, and isn't dependent on uninitialized data. * **Uninitialized data structure allocated or read?** No, `chacha_zeroize_state` is a clear operation, using `memzero_explicit` or a similar safe function. * **Changes to bounds checking or length calculation?** No, the length check (`src_len < POLY1305_DIGEST_SIZE`) remains the same, the addition is a zeroize *before* returning early. So, from what I can tell, this change doesn't expose or introduce any new risks from uninitialized memory. KMSAN shouldn't pick anything up here either. But, as I am prone to do, lets double check the `chacha_zeroize_state` definition to be 100% sure. |
| 30/3 | 2026/10/04 05:21 | tool | grepper |
0mArgs:{
"Expression": "chacha_zeroize_state"
}Results: {
"Output": "drivers/char/random.c=386=static void _get_random_bytes(void *buf, size_t len)\n--\ndrivers/char/random.c-414-\ndrivers/char/random.c:415:\tchacha_zeroize_state(\u0026chacha_state);\ndrivers/char/random.c-416-}\n--\ndrivers/char/random.c=431=static ssize_t get_random_bytes_user(struct iov_iter *iter)\n--\ndrivers/char/random.c-476-out_zero_chacha:\ndrivers/char/random.c:477:\tchacha_zeroize_state(\u0026chacha_state);\ndrivers/char/random.c-478-\treturn ret ? ret : -EFAULT;\n--\ninclude/crypto/chacha.h=91=static inline void chacha20_crypt(struct chacha_state *state,\n--\ninclude/crypto/chacha.h-96-\ninclude/crypto/chacha.h:97:static inline void chacha_zeroize_state(struct chacha_state *state)\ninclude/crypto/chacha.h-98-{\n--\nlib/crypto/chacha-block-generic.c=77=void chacha_block_generic(struct chacha_state *state,\n--\nlib/crypto/chacha-block-generic.c-90-\nlib/crypto/chacha-block-generic.c:91:\tchacha_zeroize_state(\u0026permuted_state);\nlib/crypto/chacha-block-generic.c-92-}\n--\nlib/crypto/chacha-block-generic.c=106=void hchacha_block_generic(const struct chacha_state *state,\n--\nlib/crypto/chacha-block-generic.c-115-\nlib/crypto/chacha-block-generic.c:116:\tchacha_zeroize_state(\u0026permuted_state);\nlib/crypto/chacha-block-generic.c-117-}\n--\nlib/crypto/chacha20poly1305.c=55=__chacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,\n--\nlib/crypto/chacha20poly1305.c-84-\nlib/crypto/chacha20poly1305.c:85:\tchacha_zeroize_state(chacha_state);\nlib/crypto/chacha20poly1305.c-86-\tmemzero_explicit(\u0026b, sizeof(b));\n--\nlib/crypto/chacha20poly1305.c=126=__chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,\n--\nlib/crypto/chacha20poly1305.c-140-\tif (unlikely(src_len \u003c POLY1305_DIGEST_SIZE)) {\nlib/crypto/chacha20poly1305.c:141:\t\tchacha_zeroize_state(chacha_state);\nlib/crypto/chacha20poly1305.c-142-\t\treturn false;\n--\nlib/crypto/chacha20poly1305.c-168-\nlib/crypto/chacha20poly1305.c:169:\tchacha_zeroize_state(chacha_state);\nlib/crypto/chacha20poly1305.c-170-\treturn !ret;\n--\nlib/crypto/chacha20poly1305.c=212=bool chacha20poly1305_crypt_sg_inplace(struct scatterlist *src,\n--\nlib/crypto/chacha20poly1305.c-330-\nlib/crypto/chacha20poly1305.c:331:\tchacha_zeroize_state(\u0026chacha_state);\nlib/crypto/chacha20poly1305.c-332-\tmemzero_explicit(\u0026b, sizeof(b));\n"
} |
| 31/3 | 2026/10/04 05:21 | llm | kmsan-evaluator |
0mModel:gemini-3.8-flash Args: null Results: null Tokens: input: 8202 output: 171 thoughts: 282 Thoughts: **Analyzing Chacha20poly1305 Decryption and Zeroization** Okay, so I've been reviewing this code, specifically focusing on the `__chacha20poly1305_encrypt` and `__chacha20poly1305_decrypt` functions. It appears that `__chacha20poly1305_encrypt` proactively zeroizes the `chacha_state` internally using `chacha_zeroize_state(chacha_state)` before it exits. The original implementation was inconsistent, however. While `__chacha20poly1305_encrypt` was doing this, the corresponding decryption function, `__chacha20poly1305_decrypt`, was *not* performing this critical zeroization internally. Consequently, this inconsistency resulted in `chacha20poly1305_decrypt` explicitly calling `chacha_zeroize_state` after calling `__chacha20poly1305_decrypt`, as well as a missed call by `xchacha20poly1305_decrypt`. This is a clear security concern, because we need to ensure sensitive key data is scrubbed before we return. My proposed solution is to move `chacha_zeroize_state(chacha_state)` *into* the `__chacha20poly1305_decrypt` function itself. This matches the behavior of the encryption side and guarantees that the sensitive state is zeroized in *all* decryption calls, including those that might result in early exits due to error conditions. That level of comprehensive sanitization is very important. The fix is straightforward: it solely zeroes the memory (with `memzero_explicit`) associated with the sensitive key state, and this is done purely for good key hygiene before the function returns. The code doesn't read any uninitialized memory, doesn't copy anything to user space, and doesn't rely on or create any branches or logic based on uninitialized memory, so I don't see any KMSAN-related issues. This should be a pretty clean fix. |
| 32/3 | 2026/10/04 05:21 | tool | set-results |
0mArgs:{
"KMSANReasoning": "The patch moves the zeroization of `chacha_state` via `chacha_zeroize_state()` into `__chacha20poly1305_decrypt()`, ensuring the ChaCha state is wiped on all exit paths (including the early-return path when `src_len \u003c POLY1305_DIGEST_SIZE`) and for all callers (including `xchacha20poly1305_decrypt()`).\n\nThis is a cryptographic hygiene change that only explicitly zeroes out memory buffers before returning. It does not introduce, read, branch on, or leak uninitialized memory to user space, nor does it alter memory allocation or buffer bounds. Therefore, KMSAN is not applicable.",
"NeedsKMSAN": false
}Results: {
"KMSANReasoning": "The patch moves the zeroization of `chacha_state` via `chacha_zeroize_state()` into `__chacha20poly1305_decrypt()`, ensuring the ChaCha state is wiped on all exit paths (including the early-return path when `src_len \u003c POLY1305_DIGEST_SIZE`) and for all callers (including `xchacha20poly1305_decrypt()`).\n\nThis is a cryptographic hygiene change that only explicitly zeroes out memory buffers before returning. It does not introduce, read, branch on, or leak uninitialized memory to user space, nor does it alter memory allocation or buffer bounds. Therefore, KMSAN is not applicable.",
"NeedsKMSAN": false
} |
| Total Calls | Total Tokens | Avg Tokens | Total Duration (Seconds) | Avg Duration (Seconds) |
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| Total Calls | Total Duration (Seconds) | Avg Duration (Seconds) |
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