diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-02-01 08:33:53 -0800 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-03-16 02:18:57 +0000 |
| commit | 35558f807792c21900e23046d97d7c6458f48c75 (patch) | |
| tree | 4cfd3fa65ccdfb3d10c0c32405ad923e2ffed96e /net | |
| parent | 27562537ad98909237e0cf1f25b049298edbb800 (diff) | |
tcp: fix 0 divide in __tcp_select_window()
[ Upstream commit 06425c308b92eaf60767bc71d359f4cbc7a561f8 ]
syszkaller fuzzer was able to trigger a divide by zero, when
TCP window scaling is not enabled.
SO_RCVBUF can be used not only to increase sk_rcvbuf, also
to decrease it below current receive buffers utilization.
If mss is negative or 0, just return a zero TCP window.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_output.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 8327d1150c16..1c96e9b25e58 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1923,9 +1923,11 @@ u32 __tcp_select_window(struct sock *sk) int full_space = min_t(int, tp->window_clamp, tcp_full_space(sk)); int window; - if (mss > full_space) + if (unlikely(mss > full_space)) { mss = full_space; - + if (mss <= 0) + return 0; + } if (free_space < (full_space >> 1)) { icsk->icsk_ack.quick = 0; |