ksmbd: serialize oplock close with pending break ownership

Summary

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.

Timeline

1. Sep 17, 2026, 4:06 PM UTCCVE published
2. Oct 21, 2026, 12:50 PM UTCRecord last updated

Affected versions

• Linux Linux

  From e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 · fixed in 7148a6c06ddf1c263a1cf422bee541f24d3d3926; From e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 · fixed in 7d6e682b7633120c2f93400b8c6f335d9d8e5318; From e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 · fixed in dc1e34f78dfab755fab9ad820ac5f82348fe1792; From e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 · fixed in 5f97bac88bfb333f426f01c118b8235e75af8d96; From e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 · fixed in b0148dc5625dbfd50596ac63c7487c12e8a8ab03

• Linux Linux

  5.15

• KernelLinux

  From 5.15.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.114; From 6.13.0 · fixed in 6.18.57; From 6.19.0 · fixed in 7.2.6

References 5