CVE-2026-90167ksmbd: serialize oplock close with pending break ownership

Official description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: serialize oplock close with pending break ownership close may abort an in-flight oplock break while another breaker already holds an opinfo reference. Releasing pending_break wakes that waiter, but without serializing the close transition with bit acquisition it can become a new break owner through the test_and_set_bit() fast path. It can then overwrite OPLOCK_CLOSING with OPLOCK_ACK_WAIT and continue a break for a dying opinfo. Make OPLOCK_CLOSING terminal once the opinfo is removed from the inode list. Serialize that transition, pending_break acquisition, and OPLOCK_ACK_WAIT setup with an opinfo state lock. A breaker which loses the race releases its ownership and returns -ENOENT. Explicitly wake pending_break waiters during close so they can observe the terminal state. Also prevent ACK and timeout paths from replacing OPLOCK_CLOSING with OPLOCK_STATE_NONE.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/02a31a30ccd09f3ff35ab5861c04209c381aa5dd
• https://git.kernel.org/stable/c/7148a6c06ddf1c263a1cf422bee541f24d3d3926
• https://git.kernel.org/stable/c/7d6e682b7633120c2f93400b8c6f335d9d8e5318
• https://git.kernel.org/stable/c/dc1e34f78dfab755fab9ad820ac5f82348fe1792
• https://git.kernel.org/stable/c/5f97bac88bfb333f426f01c118b8235e75af8d96
• https://git.kernel.org/stable/c/b0148dc5625dbfd50596ac63c7487c12e8a8ab03