From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Eric Dumazet <edumazet@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Neal Cardwell <ncardwell@google.com>,
"David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.4 04/20] tcp: fix 0 divide in __tcp_select_window()
Date: Thu, 16 Feb 2017 09:53:34 -0800 [thread overview]
Message-ID: <20170216175259.698639767@linuxfoundation.org> (raw)
In-Reply-To: <20170216175259.514980415@linuxfoundation.org>
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@google.com>
[ 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ipv4/tcp_output.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2383,9 +2383,11 @@ u32 __tcp_select_window(struct sock *sk)
int full_space = min_t(int, tp->window_clamp, allowed_space);
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;
next prev parent reply other threads:[~2017-02-16 18:06 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-16 17:53 [PATCH 4.4 00/20] 4.4.50-stable review Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 01/20] can: Fix kernel panic at security_sock_rcv_skb Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 02/20] ipv6: fix ip6_tnl_parse_tlv_enc_lim() Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 03/20] ipv6: pointer math error in ip6_tnl_parse_tlv_enc_lim() Greg Kroah-Hartman
2017-02-16 17:53 ` Greg Kroah-Hartman [this message]
2017-02-16 17:53 ` [PATCH 4.4 05/20] net: use a work queue to defer net_disable_timestamp() work Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 06/20] ipv4: keep skb->dst around in presence of IP options Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 07/20] netlabel: out of bound access in cipso_v4_validate() Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 08/20] ip6_gre: fix ip6gre_err() invalid reads Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 09/20] ipv6: tcp: add a missing tcp_v6_restore_cb() Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 10/20] tcp: avoid infinite loop in tcp_splice_read() Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 11/20] tun: read vnet_hdr_sz once Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 12/20] macvtap: read vnet_hdr_size once Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 13/20] mlx4: Invoke softirqs after napi_reschedule Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 14/20] sctp: avoid BUG_ON on sctp_wait_for_sndbuf Greg Kroah-Hartman
2017-02-21 16:08 ` Ben Hutchings
2017-02-21 16:56 ` Marcelo
2017-02-21 19:54 ` Marcelo Ricardo Leitner
2017-02-16 17:53 ` [PATCH 4.4 15/20] sit: fix a double free on error path Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 16/20] net: introduce device min_header_len Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 17/20] packet: round up linear to header len Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 18/20] ping: fix a null pointer dereference Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 19/20] l2tp: do not use udp_ioctl() Greg Kroah-Hartman
2017-02-16 17:53 ` [PATCH 4.4 20/20] tcp: fix mark propagation with fwmark_reflect enabled Greg Kroah-Hartman
2017-02-17 10:37 ` [PATCH 4.4 00/20] 4.4.50-stable review Guenter Roeck
[not found] ` <58a74eeb.c910190a.1e315.c4dd@mx.google.com>
2017-02-17 23:43 ` Greg Kroah-Hartman
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