diff options
| author | Eric Dumazet <edumazet@google.com> | 2019-10-10 20:17:38 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-10-13 10:13:08 -0700 |
| commit | d983ea6f16b835dcde2ee9a58a1e764ce68bfccc (patch) | |
| tree | 2bc283f36a6769e0247c49420f0c2149f147f08c /net/core | |
| parent | 8caf8a91f34d55e8e3b1355ee8d658cb472146e2 (diff) | |
| download | linux-d983ea6f16b835dcde2ee9a58a1e764ce68bfccc.tar.bz2 | |
tcp: add rcu protection around tp->fastopen_rsk
Both tcp_v4_err() and tcp_v6_err() do the following operations
while they do not own the socket lock :
fastopen = tp->fastopen_rsk;
snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
The problem is that without appropriate barrier, the compiler
might reload tp->fastopen_rsk and trigger a NULL deref.
request sockets are protected by RCU, we can simply add
the missing annotations and barriers to solve the issue.
Fixes: 168a8f58059a ("tcp: TCP Fast Open Server - main code path")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/request_sock.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/request_sock.c b/net/core/request_sock.c index c9bb00008528..f35c2e998406 100644 --- a/net/core/request_sock.c +++ b/net/core/request_sock.c @@ -96,7 +96,7 @@ void reqsk_fastopen_remove(struct sock *sk, struct request_sock *req, fastopenq = &inet_csk(lsk)->icsk_accept_queue.fastopenq; - tcp_sk(sk)->fastopen_rsk = NULL; + RCU_INIT_POINTER(tcp_sk(sk)->fastopen_rsk, NULL); spin_lock_bh(&fastopenq->lock); fastopenq->qlen--; tcp_rsk(req)->tfo_listener = false; |