CVEvulnerability
CVE-2025-39819
5.5 MEDIUM
Official page ↗
- Status
- Modified
- Published
- 2025-09-16
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 ([email protected])
- 5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Description
In the Linux kernel, the following vulnerability has been resolved:
fs/smb: Fix inconsistent refcnt update
A possible inconsistent update of refcount was identified in `smb2_compound_op`.
Such inconsistent update could lead to possible resource leaks.
Why it is a possible bug:
1. In the comment section of the function, it clearly states that the
reference to `cfile` should be dropped after calling this function.
2. Every control flow path would check and drop the reference to
`cfile`, except the patched one.
3. Existing callers would not handle refcount update of `cfile` if
-ENOMEM is returned.
To fix the bug, an extra goto label "out" is added, to make sure that the
cleanup logic would always be respected. As the problem is caused by the
allocation failure of `vars`, the cleanup logic between label "finished"
and "out" can be safely ignored. According to the definition of function
`is_replayable_error`, the error code of "-ENOMEM" is not recoverable.
Therefore, the replay logic also gets ignored.
Affected configurations
• linux linux kernel (>= 5.8 < 6.1.150)
• linux linux kernel (>= 6.2 < 6.6.104)
• linux linux kernel (>= 6.7 < 6.12.45)
• linux linux kernel (>= 6.13 < 6.16.5)
• linux linux kernel 6.17
• debian debian linux 11.0
References
- https://git.kernel.org/stable/c/3fc11ff13fbc2749871d6ac2141685cf54699997 Patch
- https://git.kernel.org/stable/c/4191ea1f0bb3e27d65c5dcde7bd00e709ec67141 Patch
- https://git.kernel.org/stable/c/4735f5991f51468b85affb8366b7067248457a71 Patch
- https://git.kernel.org/stable/c/ab529e6ca1f67bcf31f3ea80c72bffde2e9e053e Patch
- https://git.kernel.org/stable/c/cc82c6dff548f0066a51a6e577c7454e7d26a968 Patch
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Third Party Advisory
- https://cert-portal.siemens.com/productcert/html/ssa-032379.html cert-portal.siemens.com