CVE-2026-80982

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.