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+82bbd65569c49c6c0...@syzkaller.appspotmail.com Signed-off-by: Steffen Klassert <steffen.klass...@secunet.com> --- 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 f8b918c766b0..b1338e576d00 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 333a478aa161..dd9627490c7c 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; -- 2.14.1