Answer in brief
CVE-2025-40320 records a Critical severity (CVSS 9.8) vulnerability in smb: client: fix potential cfid UAF in smb2_query_info_compound. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 9.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=433042a91f9373241307725b52de573933ffedbf <939c4e33005e2a56ea8fcedddf0da92df864bd3b || >=4f1fffa2376922f3d1d506e49c0fd445b023a28e <327f89c21601ebb7889f8c97754b76f08ce95a0c || >=4f1fffa2376922f3d1d506e49c0fd445b023a28e <b556c278d43f4707a9073ca74d55581b4f279806 || >=4f1fffa2376922f3d1d506e49c0fd445b023a28e <5c76f9961c170552c1d07c830b5e145475151600 || >=6.6.32 <6.6.117 | 939c4e33005e2a56ea8fcedddf0da92df864bd3b, 327f89c21601ebb7889f8c97754b76f08ce95a0c, b556c278d43f4707a9073ca74d55581b4f279806, 5c76f9961c170552c1d07c830b5e145475151600, 6.6.117 |
| Linux/Linuxgeneric | 6.8 | Not reported |
Published upstream
Dec 8, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 15, 2026
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential cfid UAF in smb2_query_info_compound When smb2_query_info_compound() retries, a previously allocated cfid may have been freed in the first attempt. Because cfid wasn't reset on replay, later cleanup could act on a stale pointer, leading to a potential use-after-free. Reinitialize cfid to NULL under the replay label. Example trace (trimmed): refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 11224 at ../lib/refcount.c:28 refcount_warn_saturate+0x9c/0x110 [...] RIP: 0010:refcount_warn_saturate+0x9c/0x110 [...] Call Trace: <TASK> smb2_query_info_compound+0x29c/0x5c0 [cifs f90b72658819bd21c94769b6a652029a07a7172f] ? step_into+0x10d/0x690 ? __legitimize_path+0x28/0x60 smb2_queryfs+0x6a/0xf0 [cifs f90b72658819bd21c94769b6a652029a07a7172f] smb311_queryfs+0x12d/0x140 [cifs f90b72658819bd21c94769b6a652029a07a7172f] ? kmem_cache_alloc+0x18a/0x340 ? getname_flags+0x46/0x1e0 cifs_statfs+0x9f/0x2b0 [cifs f90b72658819bd21c94769b6a652029a07a7172f] statfs_by_dentry+0x67/0x90 vfs_statfs+0x16/0xd0 user_statfs+0x54/0xa0 __do_sys_statfs+0x20/0x50 do_syscall_64+0x58/0x80
Quoted source text, attributed separately from HOL analysis.