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| author |   Eric Dumazet <edumazet@google.com> | 2019-06-07 12:23:48 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-06-09 19:42:23 -0700 |
| commit | 392096736a06bc9d8f2b42fd4bb1a44b245b9fed (patch) | |
| tree | 49e47af6d0fe976d4ea59af736c46f590c826334 /net/ipv6/tcp_ipv6.c | |
| parent | Merge branch 'Avoid-local_irq_save-and-use-napi_alloc_frag-where-possible' (diff) | |
| download | linux-dev-392096736a06bc9d8f2b42fd4bb1a44b245b9fed.tar.xz linux-dev-392096736a06bc9d8f2b42fd4bb1a44b245b9fed.zip | |
ipv6: tcp: fix potential NULL deref in tcp_v6_send_reset()
syzbot found a crash in tcp_v6_send_reset() caused by my latest
change.
Problem is that if an skb has been queued to socket prequeue,
skb_dst(skb)->dev can not anymore point to the device.
Fortunately in this case the socket pointer is not NULL.
A similar issue has been fixed in commit 0f85feae6b71 ("tcp: fix
more NULL deref after prequeue changes"), I should have known better.
Fixes: 323a53c41292 ("ipv6: tcp: enable flowlabel reflection in some RST packets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/tcp_ipv6.c')
| -rw-r--r-- | net/ipv6/tcp_ipv6.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index d8d18386c99a..c1da52c7f990 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -934,7 +934,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) if (!sk && !ipv6_unicast_destination(skb)) return; - net = dev_net(skb_dst(skb)->dev); + net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); #ifdef CONFIG_TCP_MD5SIG rcu_read_lock(); hash_location = tcp_parse_md5sig_option(th); |