summary refs log tree commit diff
path: root/net/ipv4/tcp.c
diff options
context:
space:
mode:
authorEric Dumazet <edumazet@google.com>2016-11-02 07:53:17 -0700
committerDavid S. Miller <davem@davemloft.net>2016-11-03 15:33:30 -0400
commitac9e70b17ecd7c6e933ff2eaf7ab37429e71bf4d (patch)
tree781677be717b11066e303449ee4abd787048816e /net/ipv4/tcp.c
parent9512925a2cc2b1cd0206bb93bad200a69716f998 (diff)
downloadlinux-ac9e70b17ecd7c6e933ff2eaf7ab37429e71bf4d.tar.gz
tcp: fix potential memory corruption
Imagine initial value of max_skb_frags is 17, and last
skb in write queue has 15 frags.

Then max_skb_frags is lowered to 14 or smaller value.

tcp_sendmsg() will then be allowed to add additional page frags
and eventually go past MAX_SKB_FRAGS, overflowing struct
skb_shared_info.

Fixes: 5f74f82ea34c ("net:Add sysctl_max_skb_frags")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Hans Westgaard Ry <hans.westgaard.ry@oracle.com>
Cc: HÃ¥kon Bugge <haakon.bugge@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp.c')
-rw-r--r--net/ipv4/tcp.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 3251fe71f39f..18238ef8135a 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1241,7 +1241,7 @@ new_segment:
 
 			if (!skb_can_coalesce(skb, i, pfrag->page,
 					      pfrag->offset)) {
-				if (i == sysctl_max_skb_frags || !sg) {
+				if (i >= sysctl_max_skb_frags || !sg) {
 					tcp_mark_push(tp, skb);
 					goto new_segment;
 				}