CVE-2026-74692
What it is
In the Linux kernel, the following vulnerability has been resolved: net/smc: fix TOCTOU race between smc_listen_out() and listener close smc_listen_out() reads lsmc->sk.sk_state without the listener lock, then acquires lock_sock_nested() only after the check passes. This opens a window where smc_close_active() can transition the listener to SMC_CLOSED, call smc_close_cleanup_listen() to drain the accept queue, and release the lock, all between the lockless read and the delayed lock acquisition: smc_listen_work (smc_hs_wq) smc_close_active() ------------------------------- ------------------------- release_sock(child) if (sk_state == SMC_LISTEN) TRUE lock_sock(listener) sk_state = SMC_CLOSED smc_close_cleanup_listen() release_sock(listener) flush_work(tcp_listen_work) lock_sock_nested(listener) smc_accept_enqueue(listener, child) /* child enqueued on dead listener */ smc_close_active() flushes only tcp_listen_work. Work items already dispatched onto smc_hs_wq for the CLC handshake continue running unguarded. smc_accept_enqueue() takes a sock_hold() on the child that is never released, so the child smc_sock, its clcsock, and the reference all leak. A remote peer that opens TCP connections while the server calls close() can exhaust kernel memory. Move lock_sock_nested() to before the sk_state check so that the test and the enqueue are atomic under the listener lock.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of service disruption.
- Exploit odds
- 0.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.5% in the next 30 days (EPSS).
- Severity: 7.5 HIGH (CVSS).
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.5% · EPSS, next 30 days
- Record status
- Received
Attack profile CVSS 3.1 · 7.5
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-74692.md and follow it. Check whether this project is affected by CVE-2026-74692. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
References
- https://git.kernel.org/stable/c/00f89433777236ced4771211047fb5d4cd581cea
- https://git.kernel.org/stable/c/01865e1ddb126b25ac9eba5cdd7ec49e11183a64
- https://git.kernel.org/stable/c/185a4caeecabc150106deda1da170b09f2ad803f
- https://git.kernel.org/stable/c/53c7938d8bcfde3296ec1a347ba2a9393c1fdcfa
- https://git.kernel.org/stable/c/78e5ebcd1c10ed7c8bda0a99e0abd5b62da86d67
- https://git.kernel.org/stable/c/feb71634bb1abab3e8fb5cde874b27001cc1282e
- https://git.kernel.org/stable/c/ff5bcd804b5bc5c64736b7d318c20e12ea9506b8