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authorEric Dumazet <edumazet@google.com>2019-02-15 13:36:21 -0800
committerDavid S. Miller <davem@davemloft.net>2019-02-17 15:46:58 -0800
commit2c4cc9712364c051b1de2d175d5fbea6be948ebf (patch)
tree26a96c9f5c6762780a5941fddcb326eb8a555449
parent04c03114be82194d4a4858d41dba8e286ad1787c (diff)
downloadlinux-2c4cc9712364c051b1de2d175d5fbea6be948ebf.tar.bz2
tcp: tcp_v4_err() should be more careful
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>
-rw-r--r--net/ipv4/tcp_ipv4.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index efc6fef692ff..ec3cea9d6828 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -536,12 +536,15 @@ int tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
if (sock_owned_by_user(sk))
break;
+ skb = tcp_rtx_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_rtx_queue_head(sk);
tcp_mstamp_refresh(tp);
delta_us = (u32)(tp->tcp_mstamp - tcp_skb_timestamp_us(skb));