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authorEric Dumazet <edumazet@google.com>2019-02-15 13:36:21 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-02-23 09:06:43 +0100
commit55103aa317afce598ee93ba3a3c5eb64ce4e6238 (patch)
tree11fb662fdac9e38bfd65e3e4c350bdd27482660e
parent8565b7fb8dfa0bc97818c2417e813de6147f5d76 (diff)
tcp: tcp_v4_err() should be more careful
[ Upstream commit 2c4cc9712364c051b1de2d175d5fbea6be948ebf ] ICMP handlers are not very often stressed, we should make them more resilient to bugs that might surface in the future. If there is no packet in retransmit queue, we should avoid a NULL deref. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: soukjin bae <soukjin.bae@samsung.com> Acked-by: Neal Cardwell <ncardwell@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/ipv4/tcp_ipv4.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 31b34c0c2d5f..e593301f442f 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -475,14 +475,15 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
if (sock_owned_by_user(sk))
break;
+ skb = tcp_write_queue_head(sk);
+ if (WARN_ON_ONCE(!skb))
+ break;
+
icsk->icsk_backoff--;
icsk->icsk_rto = tp->srtt_us ? __tcp_set_rto(tp) :
TCP_TIMEOUT_INIT;
icsk->icsk_rto = inet_csk_rto_backoff(icsk, TCP_RTO_MAX);
- skb = tcp_write_queue_head(sk);
- BUG_ON(!skb);
-
tcp_mstamp_refresh(tp);
delta_us = (u32)(tp->tcp_mstamp - skb->skb_mstamp);
remaining = icsk->icsk_rto -