CVE-2025-40320smb: client: fix potential cfid UAF in smb2_query_info_compound
- 9.8CriticalCVSS base score
- 0.45%Exploitation in 30 daysEPSS · top 61% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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
Timeline
ID reserved
By Linux
- 8 months later
· 8 months later
Published
- 10 months later
· 10 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Deferred | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.45% · top 61% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
- affected 433042a91f9373241307725b52de573933ffedbf – < 939c4e33005e2a56ea8fcedddf0da92df864bd3b
- affected 4f1fffa2376922f3d1d506e49c0fd445b023a28e – < 327f89c21601ebb7889f8c97754b76f08ce95a0c
- affected 4f1fffa2376922f3d1d506e49c0fd445b023a28e – < b556c278d43f4707a9073ca74d55581b4f279806
- affected 4f1fffa2376922f3d1d506e49c0fd445b023a28e – < 5c76f9961c170552c1d07c830b5e145475151600
- affected 6.6.32 – < 6.6.117
- affected 6.8
- unaffected < 6.8
- unaffected 6.6.117 – ≤ 6.6.*
- unaffected 6.12.58 – ≤ 6.12.*
- unaffected 6.17.8 – ≤ 6.17.*
- unaffected 6.18 – ≤ *
References
References4
- https://git.kernel.org/stable/c/939c4e33005e2a56ea8fcedddf0da92df864bd3b (opens in a new tab)
- https://git.kernel.org/stable/c/327f89c21601ebb7889f8c97754b76f08ce95a0c (opens in a new tab)
- https://git.kernel.org/stable/c/b556c278d43f4707a9073ca74d55581b4f279806 (opens in a new tab)
- https://git.kernel.org/stable/c/5c76f9961c170552c1d07c830b5e145475151600 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-201625 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-40320)Record last updated .