CVE-2026-97556: Linux kernel · smb: client: avoid leaking refcount when cifs_sb_tlink() fails
Source GCVE Database
Not known to be exploited · fixed in f1fd8a84181b3af03c508e0b02b4877945dd070a : update Linux kernel when convenient.
Data as of 30 Oct 2026, 17:33 UTC
Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD
Thin evidence
One scorer or none- Patch
- Available – fixed in f1fd8a84181b3af03c508e0b02b4877945dd070a, e9c5bcc88b8337157e480c85a6d2f326bc265012, dd03fd658ea59821505e0e643b6b7cbdf51c4e1d +7
Exploitation evidence
Disclosed: evidence found.
CVE published 25 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix has been applied to the Linux kernel to properly drop the leaked reference in the failure path of cifs_sb_tlink(). Users should update to the fixed kernel version once available. No additional mitigations are indicated.
Description
A reference count leak in the Linux kernel's SMB client code was fixed. The issue occurred when cifs_sb_tlink() failed in multiuser setups, causing cifs_oplock_break() to skip dropping a file reference. This led to busy inodes and a crash during unmount of CIFS filesystems. The fix ensures the reference is properly dropped to prevent this crash.
References
- nvd.nist.gov/vuln/detail/CVE-2026-97556 (opens in a new tab)
- git.kernel.org/stable/c/1d1b0f1d812a4011a57bc6c70492c34a2e46c6dd (opens in a new tab)
- git.kernel.org/stable/c/23b26f4408ac3f35a482d2e5cf6fc865d4201b71 (opens in a new tab)
- git.kernel.org/stable/c/55c5f095d4df14271b238f826e1392fda7b6e60e (opens in a new tab)
- git.kernel.org/stable/c/9ec991e148368e3207e98134c509a625097f7693 (opens in a new tab)
- git.kernel.org/stable/c/dd03fd658ea59821505e0e643b6b7cbdf51c4e1d (opens in a new tab)
- git.kernel.org/stable/c/e9c5bcc88b8337157e480c85a6d2f326bc265012 (opens in a new tab)
- git.kernel.org/stable/c/f1fd8a84181b3af03c508e0b02b4877945dd070a (opens in a new tab)