In the Linux kernel, the following vulnerability has been resolved:

sunrpc: pin svc_xprt across the asynchronous TLS handshake callback

svc_tcp_handshake() stores the raw svc_xprt pointer in
tls_handshake_args.ta_data and submits the request through
tls_server_hello_x509(). The handshake core takes only
sock_hold(req->hr_sk); nothing references the embedding struct
svc_sock that svc_tcp_handshake_done() reaches via container_of().

Two close races leave the in-flight callback writing through a freed
svc_sock. svc_sock_free() calls tls_handshake_cancel() and discards
its return value: a false return means handshake_complete() has
already set HANDSHAKE_F_REQ_COMPLETED but hp_done() may not have
finished, yet svc_sock_free() proceeds to kfree(svsk). The
cancel-loser fall-through inside svc_tcp_handshake() itself produces
the same window: when wait_for_completion_interruptible_timeout()
returns <= 0 (timeout or signal) and tls_handshake_cancel() returns
false, the function does not drain, returns, and svc_handle_xprt()
calls svc_xprt_received(), which clears XPT_BUSY and can drop the
last reference. A concurrent close then runs svc_sock_free() while
svc_tcp_handshake_done() is still updating xpt_flags and walking
svsk->sk_handshake_done.

The corruption surfaces as set_bit/clear_bit RMW into the freed
xpt_flags slab slot and as complete_all() walking and writing the
freed wait_queue_head_t list embedded in sk_handshake_done -- a
slab-corruption primitive, not a benign read. The path is reachable
on any TLS-enabled NFS server whenever a connection close overlaps
the tlshd downcall delivery window; the interruptible wait means
signal delivery suffices, not just SVC_HANDSHAKE_TO expiry.

Take svc_xprt_get(xprt) immediately before tls_server_hello_x509()
so the in-flight callback owns its own reference. Release it on the
two edges where the callback is guaranteed not to fire -- submission
failure from tls_server_hello_x509() and a successful
tls_handshake_cancel() -- and at the tail of
svc_tcp_handshake_done() after complete_all().

[cel: rewrote commit message to describe the actual change]

https://git.kernel.org/stable/c/083e9c2ec7e8bb13b79c9fd7b337abdd758ecc5f

https://git.kernel.org/stable/c/2d4f97d13fff91e0bc539216be88b884b544d49f

https://git.kernel.org/stable/c/3f9ee75a97a769be258784c22b89657acb5ed9bd

https://git.kernel.org/stable/c/4f988f3a2808fb659f3880c282041ff067acad78

https://git.kernel.org/stable/c/f3b55945dd99f29d83e1965d0141040a35262346

[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","programFiles":["net/sunrpc/svcsock.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","versions":[{"version":"b3cbf98e2fdf3cb147a95161560cd25987284330","lessThan":"f3b55945dd99f29d83e1965d0141040a35262346","versionType":"git","status":"affected"},{"version":"b3cbf98e2fdf3cb147a95161560cd25987284330","lessThan":"2d4f97d13fff91e0bc539216be88b884b544d49f","versionType":"git","status":"affected"},{"version":"b3cbf98e2fdf3cb147a95161560cd25987284330","lessThan":"3f9ee75a97a769be258784c22b89657acb5ed9bd","versionType":"git","status":"affected"},{"version":"b3cbf98e2fdf3cb147a95161560cd25987284330","lessThan":"083e9c2ec7e8bb13b79c9fd7b337abdd758ecc5f","versionType":"git","status":"affected"},{"version":"b3cbf98e2fdf3cb147a95161560cd25987284330","lessThan":"4f988f3a2808fb659f3880c282041ff067acad78","versionType":"git","status":"affected"}]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","programFiles":["net/sunrpc/svcsock.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","versions":[{"version":"6.4","status":"affected"},{"version":"0","lessThan":"6.4","versionType":"semver","status":"unaffected"},{"version":"6.6.145","lessThanOrEqual":"6.6.*","versionType":"semver","status":"unaffected"},{"version":"6.12.97","lessThanOrEqual":"6.12.*","versionType":"semver","status":"unaffected"},{"version":"6.18.40","lessThanOrEqual":"6.18.*","versionType":"semver","status":"unaffected"},{"version":"7.1.5","lessThanOrEqual":"7.1.*","versionType":"semver","status":"unaffected"},{"version":"7.2-rc1","lessThanOrEqual":"*","versionType":"original_commit_for_fix","status":"unaffected"}]}]