Vulnerability in Linux

[ Description ]Official description

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix server use-after-free in cifs_chan_skip_or_disable() When a secondary channel is no longer supported by the server, cifs_chan_skip_or_disable() drops the channel reference with cifs_put_tcp_session() and then continues to use the server pointer by calling cifs_signal_cifsd_for_reconnect() on it and reading its primary_server pointer. cifs_put_tcp_session() can drop the last reference of the channel and tear it down, so both the channel and the primary server (whose reference is also dropped by cifs_put_tcp_session()) can be freed before they are signaled for reconnect. Signal the channel and the primary server and capture the primary server pointer before dropping the channel reference with cifs_put_tcp_session().

[ 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

• BSI CERT-Bund5 Oct 2026WID-SEC-2026-3743

  Linux Kernel: Multiple vulnerabilities Translated from German

  Risk mediumCVE-2026-98221CVE-2026-98181CVE-2026-98248+204 more CVEs

[ References ]References

• git.kernel.org/stable/c/0338489960ddad6368bce55e8adbc176c523093d
• git.kernel.org/stable/c/717e0a25036b6c92cecace30913b2d874a4c22b8
• git.kernel.org/stable/c/7a1b27780b113583a94256d58dabfe7c0d9286e7
• git.kernel.org/stable/c/edd52eae5fcfb8433b6bb0e7cd98db438fe01227
• git.kernel.org/stable/c/fcc0a935bb6e37ecbf7e4335061309f896f35780