CVE-2026-97556

CVE CVE-2026-97556EUVD EUVD-2026-86864Published 2026-09-25T10:21:47.000Z

What the advisory describes

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.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

Linux — Linux 5ee28bcfbaacf289eb25c662a2862542ea6ce6a7; e8f5f849ffce24490eb9449e98312b66c0dba76f <9ec991e148368e3207e98134c509a625097f7693; 6.5; e8f5f849ffce24490eb9449e98312b66c0dba76f <dd03fd658ea59821505e0e643b6b7cbdf51c4e1d; patch: 7.2.7; patch: 7.3-rc3; patch: 0; e8f5f849ffce24490eb9449e98312b66c0dba76f <23b26f4408ac3f35a482d2e5cf6fc865d4201b71; 6.4.12 <6.5; patch: 6.18.53; patch: 6.12.111; 5.15.128 <5.16; e8f5f849ffce24490eb9449e98312b66c0dba76f <1d1b0f1d812a4011a57bc6c70492c34a2e46c6dd; b99f490ea87ebcca3a429fd8837067feb56a4c7c; 6.1.47 <6.2; 6b67a6d2e50634fe127e656147c81915955e9f5e

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

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Linux — Linux

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