CVE Catalog

CVE-2026-97556

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel's SMB client, there is a reference leak in cifs_oplock_break() when cifs_sb_tlink() fails in multiuser mode. The fix releases the reference on that error path as well.

Risk Assessment

May lead to system crash on unmount due to busy inodes.

Recommendation

Update the kernel to a version with the fix that releases the reference on the error path.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS