tcp: md5: protects md5sig_info with RCU
This patch makes sure we use appropriate memory barriers before
publishing tp->md5sig_info, allowing tcp_md5_do_lookup() being used from
tcp_v4_send_reset() without holding socket lock (upcoming patch from
Shawn Lu)
Note we also need to respect rcu grace period before its freeing, since
we can free socket without this grace period thanks to
SLAB_DESTROY_BY_RCU
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Shawn Lu <shawn.lu@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index c2025f1..115389e 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -463,7 +463,7 @@
const struct tcp_sock_af_ops *af_specific;
/* TCP MD5 Signature Option information */
- struct tcp_md5sig_info *md5sig_info;
+ struct tcp_md5sig_info __rcu *md5sig_info;
#endif
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