From: Steffen Klassert <steffen.klassert@secunet.com>
Date: Fri, 5 Jan 2018 08:35:47 +0100
Subject: esp: Fix GRO when the headers not fully in the linear part of the skb.
Patch-mainline: v4.15-rc9
Git-commit: 374d1b5a81f7f9cc5e7f095ac3d5aff3f6600376
References: bsc#1076830
The GRO layer does not necessarily pull the complete headers
into the linear part of the skb, a part may remain on the
first page fragment. This can lead to a crash if we try to
pull the headers, so make sure we have them on the linear
part before pulling.
Fixes: 7785bba299a8 ("esp: Add a software GRO codepath")
Reported-by: syzbot+82bbd65569c49c6c0c4d@syzkaller.appspotmail.com
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Michal Kubecek <mkubecek@suse.cz>
---
net/ipv4/esp4_offload.c | 3 ++-
net/ipv6/esp6_offload.c | 3 ++-
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/esp4_offload.c b/net/ipv4/esp4_offload.c
index 227e06d33caf..abfa0332e000 100644
--- a/net/ipv4/esp4_offload.c
+++ b/net/ipv4/esp4_offload.c
@@ -38,7 +38,8 @@ static struct sk_buff **esp4_gro_receive(struct sk_buff **head,
__be32 spi;
int err;
- skb_pull(skb, offset);
+ if (!pskb_pull(skb, offset))
+ return NULL;
if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0)
goto out;
diff --git a/net/ipv6/esp6_offload.c b/net/ipv6/esp6_offload.c
index be470db6cee2..4ed703a51efe 100644
--- a/net/ipv6/esp6_offload.c
+++ b/net/ipv6/esp6_offload.c
@@ -60,7 +60,8 @@ static struct sk_buff **esp6_gro_receive(struct sk_buff **head,
int nhoff;
int err;
- skb_pull(skb, offset);
+ if (!pskb_pull(skb, offset))
+ return NULL;
if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0)
goto out;
--
2.16.1