Currently we check sk_user_data is non NULL to determine if the sk
exists in a map. However, this is not sufficient to ensure the psock
or the ULP ops are not in use by another user, such as kcm or TLS. To
avoid this when adding a sock to a map also verify it is of the
correct ULP type. Additionally, when releasing a psock verify that
it is the TCP_ULP_BPF type before releasing the ULP. The error case
where we abort an update due to ULP collision can cause this error
path.
For example,
__sock_map_ctx_update_elem()
[...]
err = tcp_set_ulp_id(sock, TCP_ULP_BPF) <- collides with TLS
if (err) <- so err out here
goto out_free
[...]
out_free:
smap_release_sock() <- calling tcp_cleanup_ulp releases the
TLS ULP incorrectly.
Fixes: 2f857d0460 ("bpf: sockmap, remove STRPARSER map_flags and add multi-map support")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
597222f72a