From: Eric Dumazet <edumazet@xxxxxxxxxx>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
[ Upstream commit ac9e70b17ecd7c6e933ff2eaf7ab37429e71bf4d ]
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@xxxxxxxxxx>
Cc: Hans Westgaard Ry <hans.westgaard.ry@xxxxxxxxxx>
Cc: Håkon Bugge <haakon.bugge@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
net/ipv4/tcp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 392d3259f9ad..3e63b5fb2121 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1169,7 +1169,7 @@ 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;
}
--
2.10.2
--
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