Vulnerability in Linux

[ Description ]Official description

In the Linux kernel, the following vulnerability has been resolved: smb: client: avoid leaking refcount in cifs_queue_oplock_break() cifs_queue_oplock_break() unconditionally takes a reference on the target file before queueing cifs_oplock_break(). Only that work item decreases the reference counter again. If another oplock break arrives while that work is still queued, queue_work() will return false and not queue this second work item. As a result, we will never reach the point to drop the file reference again and are leaking this reference. This can be triggered when interacting with a slow-responding server. As a result, later unmount operations for this file system will fail with BUG: Dentry ... still in use (1) [unmount of cifs cifs] VFS: Busy inodes after unmount of cifs (cifs) kernel BUG at fs/super.c:777! Fix this by only incrementing the reference count if the work has been queued successfully. Taking it after queue_work() is safe because all three callers hold tcon->open_file_lock across the call and _cifsFileInfo_put() decrements under that same lock, so a worker that starts the handler in the window cannot drop the reference before it has been taken.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• CERT-FR16 Oct 2026CERTFR-2026-AVI-1335

  Multiple vulnerabilities in the SUSE Linux kernel Translated from French

  Multiple vulnerabilities have been discovered in the SUSE Linux kernel. Some of them allow an attacker to cause privilege escalation, remote denial of service and a breach of data confidentiality.

  CVE-2026-72436CVE-2026-74632CVE-2026-89702+602 more CVEs
• CERT-FR9 Oct 2026CERTFR-2026-AVI-1289

  Multiple vulnerabilities in the Debian LTS Linux kernel Translated from French

  Multiple vulnerabilities have been discovered in the Debian LTS Linux kernel. Some of them allow an attacker to cause privilege escalation, a breach of data confidentiality and denial of service.

  CVE-2025-38237CVE-2025-39833CVE-2025-39925+1311 more CVEs
• CERT-FR2 Oct 2026CERTFR-2026-AVI-1253

  Multiple vulnerabilities in the Debian Linux kernel Translated from French

  Multiple vulnerabilities have been discovered in the Debian Linux kernel. Some of them allow an attacker to cause privilege escalation, a breach of data confidentiality and denial of service.

  CVE-2025-38237CVE-2025-39833CVE-2025-39925+1310 more CVEs
• BSI CERT-Bund24 Sep 2026WID-SEC-2026-3579

  Linux Kernel: Multiple vulnerabilities Translated from German

  CVE-2026-97615CVE-2026-97978CVE-2026-98127+590 more CVEs

[ References ]References

• git.kernel.org/stable/c/2ed2c29dd9593637cfa25ac1eb23241b20202778
• git.kernel.org/stable/c/735a3a610136ae10f381d0909dff38e5b5c5f056
• git.kernel.org/stable/c/9f2e63f1b2d5fc5b5423424902c091123e220e7e
• git.kernel.org/stable/c/af0193bbf1ac8c0f67f972998b0cc629d6116cf6
• git.kernel.org/stable/c/de2a6bcff2659bea40c7485115b57f0ae189fc01
• git.kernel.org/stable/c/dfe7b750c7e069873a8a57a11c816831a235618a