smb: client: avoid leaking refcount when cifs_sb_tlink() fails
Summary
| CVE | CVE-2026-97556 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-25 11:17:06 UTC |
| Updated | 2026-10-03 11:18:03 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: smb: client: avoid leaking refcount when cifs_sb_tlink() fails cifs_oplock_break() takes over the reference that cifs_queue_oplock_break() acquired when it queued the work, and drops it with _cifsFileInfo_put() once the break has been processed. Only in setups with "-o multiuser", cifs_sb_tlink() may fail, at which point cifs_oplock_break() returns without putting the file reference, mirroring the reference leak we already fixed in the companion patch to cifs_queue_oplock_break(). This would trigger a crash due to busy inodes on the next unmount: BUG: Dentry ... still in use (1) [unmount of cifs cifs] VFS: Busy inodes after unmount of cifs (cifs) Drop the reference on that path as well. Doing so before the out label mirrors the normal path, which also puts the reference before cifs_done_oplock_break(). Found by Sashiko code review. The failure path was not exercised at runtime. |
Risk And Classification
EPSS: 0.002000000 probability, percentile 0.089010000 (date 2026-10-03)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 5ee28bcfbaacf289eb25c662a2862542ea6ce6a7 55c5f095d4df14271b238f826e1392fda7b6e60e git | Not specified |
| CNA | Linux | Linux | affected e8f5f849ffce24490eb9449e98312b66c0dba76f e9c5bcc88b8337157e480c85a6d2f326bc265012 git | Not specified |
| CNA | Linux | Linux | affected e8f5f849ffce24490eb9449e98312b66c0dba76f 9ec991e148368e3207e98134c509a625097f7693 git | Not specified |
| CNA | Linux | Linux | affected e8f5f849ffce24490eb9449e98312b66c0dba76f dd03fd658ea59821505e0e643b6b7cbdf51c4e1d git | Not specified |
| CNA | Linux | Linux | affected e8f5f849ffce24490eb9449e98312b66c0dba76f 1d1b0f1d812a4011a57bc6c70492c34a2e46c6dd git | Not specified |
| CNA | Linux | Linux | affected e8f5f849ffce24490eb9449e98312b66c0dba76f 23b26f4408ac3f35a482d2e5cf6fc865d4201b71 git | Not specified |
| CNA | Linux | Linux | affected b99f490ea87ebcca3a429fd8837067feb56a4c7c git | Not specified |
| CNA | Linux | Linux | affected 6b67a6d2e50634fe127e656147c81915955e9f5e git | Not specified |
| CNA | Linux | Linux | affected 6.1.47 6.1.189 semver | Not specified |
| CNA | Linux | Linux | affected 5.15.128 5.16 semver | Not specified |
| CNA | Linux | Linux | affected 6.4.12 6.5 semver | Not specified |
| CNA | Linux | Linux | affected 6.5 | Not specified |
| CNA | Linux | Linux | unaffected 6.5 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.189 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.158 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.111 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.53 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.7 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3-rc3 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/9ec991e148368e3207e98134c509a625097f7693 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/e9c5bcc88b8337157e480c85a6d2f326bc265012 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/dd03fd658ea59821505e0e643b6b7cbdf51c4e1d | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/1d1b0f1d812a4011a57bc6c70492c34a2e46c6dd | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/23b26f4408ac3f35a482d2e5cf6fc865d4201b71 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/55c5f095d4df14271b238f826e1392fda7b6e60e | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.