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| author | Guillaume Nault <gnault@redhat.com> | 2019-03-08 22:09:47 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-03-08 16:05:10 -0800 |
| commit | 9d3e1368bb45893a75a5dfb7cd21fdebfa6b47af (patch) | |
| tree | 803b92c4735eb270910bc9846273b00e65343729 /net/ipv4/syncookies.c | |
| parent | 09073525f8b9095931e5a82209b61abc7ce4c9d5 (diff) | |
| download | lwn-9d3e1368bb45893a75a5dfb7cd21fdebfa6b47af.tar.gz lwn-9d3e1368bb45893a75a5dfb7cd21fdebfa6b47af.zip | |
tcp: handle inet_csk_reqsk_queue_add() failures
Commit 7716682cc58e ("tcp/dccp: fix another race at listener
dismantle") let inet_csk_reqsk_queue_add() fail, and adjusted
{tcp,dccp}_check_req() accordingly. However, TFO and syncookies
weren't modified, thus leaking allocated resources on error.
Contrary to tcp_check_req(), in both syncookies and TFO cases,
we need to drop the request socket. Also, since the child socket is
created with inet_csk_clone_lock(), we have to unlock it and drop an
extra reference (->sk_refcount is initially set to 2 and
inet_csk_reqsk_queue_add() drops only one ref).
For TFO, we also need to revert the work done by tcp_try_fastopen()
(with reqsk_fastopen_remove()).
Fixes: 7716682cc58e ("tcp/dccp: fix another race at listener dismantle")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/syncookies.c')
| -rw-r--r-- | net/ipv4/syncookies.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index 606f868d9f3f..e531344611a0 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -216,7 +216,12 @@ struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, refcount_set(&req->rsk_refcnt, 1); tcp_sk(child)->tsoffset = tsoff; sock_rps_save_rxhash(child, skb); - inet_csk_reqsk_queue_add(sk, req, child); + if (!inet_csk_reqsk_queue_add(sk, req, child)) { + bh_unlock_sock(child); + sock_put(child); + child = NULL; + reqsk_put(req); + } } else { reqsk_free(req); } |