CVE-2026-80982 net/smc: fix use-after-free in smc_rx_pipe_buf_release()
A use-after-free in the Linux kernel's SMC network module allows attackers to execute arbitrary code or escalate privileges via a race condition during socket closure.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80982?
CVE-2026-80982 is a high-severity use after free vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net/smc: fix use-after-free in smc_rx_pipe_buf_release()
smc_rx_splice() hands RMB pages to a pipe and takes a socket reference per entry so the smc_sock stays alive until the reader finishes. The connection does not: a concurrent close runs smc_conn_free(), which releases the receive buffer back to the link group pool.
smc_rx_pipe_buf_release() tests sk_state before taking the socket lock. The state can change between the test and the lock, and smc_rx_update_cons() then dereferences conn->rmb_desc and walks conn->lgr, which smc_conn_free() has already released. On the is_reg_err path smcr_buf_unuse() frees the descriptor outright, so this is a use-after-free.
Take the socket lock first and test conn->freed instead. smc_conn_free() sets that flag before releasing anything, and every caller holds the socket lock. The two paths exclude each other: either the pipe release runs first with everything valid, or it sees the flag and skips the update.
Which versions are affected by CVE-2026-80982?
How do I fix CVE-2026-80982?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-80982 being exploited?
There is no known exploitation of CVE-2026-80982 in the wild and no public exploit code.
Sources
Also known as AZL-100202, BELL-CVE-2026-80982, DEBIAN-CVE-2026-80982, GHSA-vr9j-9w5f-vmw6, UBUNTU-CVE-2026-80982.