CVE-2026-99054
In the Linux kernel, the following vulnerability has been resolved:
tipc: destroy topsrv workqueues before closing connections
tipc_topsrv_stop() closed subscriber connections while the topology server's send and receive workqueues were still running. Socket callbacks and subscription events could then queue more work, and in-flight send/recv work could drop the last connection reference during the conn_idr walk.
That race produced several teardown failures: refcount_t addition on 0 from conn_get() on a connection whose release was blocked on idr_lock, a subsequent use-after-free in tipc_conn_close(), queue_work() on an already destroyed workqueue from the listener data-ready callback, and an RCU stall in tipc_topsrv_exit_net() while the walk spun under idr_lock.
Clear srv->listener under idr_lock so it acts as a shutdown flag, skip queue_work() once it is NULL, destroy the workqueues to flush in-flight work, and only then close the remaining connections. Refuse tipc_conn_lookup() after that flag is cleared, and drop idr_lock when the teardown walk finds no connection, so an in-flight subscription event cannot pin idr_in_use while the walk holds the lock.
v3 supersedes the narrower in-thread diff Tung Quang Nguyen posted on 2026-09-23. It keeps his teardown order and adds the lookup refusal and the empty-idr unlock.
No affected software listed.
- https://git.kernel.org/stable/c/0af8780bdfdfc91fb9127bddb9c48fab67dc9d9e
- https://git.kernel.org/stable/c/3acdd44385bc7e2e57605e073691ce69cc5a960d
- https://git.kernel.org/stable/c/7f796bb3b440d7f1b14c0e3b520462eb34f553af
- https://git.kernel.org/stable/c/da9c16568bc79140a54c1f5fcf07a0305df47b37
- https://git.kernel.org/stable/c/fb717c536af2aafeca520ff11d1e0f25f7ab8fa9
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A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
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