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authorWillem de Bruijn <willemb@google.com>2018-05-17 13:13:29 -0400
committerDavid S. Miller <davem@davemloft.net>2018-05-17 17:05:01 -0400
commit113f99c3358564a0647d444c2ae34e8b1abfd5b9 (patch)
tree9f8a2ef799de5be76bb83fb73524b2575a5759af /net/ipv4/ip_output.c
parent374edea4aaedb92964d35f68318c094b6d5c0f63 (diff)
downloadlinux-113f99c3358564a0647d444c2ae34e8b1abfd5b9.tar.bz2
net: test tailroom before appending to linear skb
Device features may change during transmission. In particular with corking, a device may toggle scatter-gather in between allocating and writing to an skb. Do not unconditionally assume that !NETIF_F_SG at write time implies that the same held at alloc time and thus the skb has sufficient tailroom. This issue predates git history. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_output.c')
-rw-r--r--net/ipv4/ip_output.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 83c73bab2c3d..d54abc097800 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1045,7 +1045,8 @@ alloc_new_skb:
if (copy > length)
copy = length;
- if (!(rt->dst.dev->features&NETIF_F_SG)) {
+ if (!(rt->dst.dev->features&NETIF_F_SG) &&
+ skb_tailroom(skb) >= copy) {
unsigned int off;
off = skb->len;