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| author | Lorenzo Bianconi <lorenzo.bianconi@redhat.com> | 2019-04-09 11:47:20 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-27 09:34:00 +0200 |
| commit | b1aaee5a97c9d6557bec13cf22d3db888c91509c (patch) | |
| tree | be24c72434eedccfc383c5f9789b937c0ae20a7c /net/ipv4 | |
| parent | dc20066a631c4cba287cd3a9920718a6e6658a76 (diff) | |
net: fou: do not use guehdr after iptunnel_pull_offloads in gue_udp_recv
[ Upstream commit 988dc4a9a3b66be75b30405a5494faf0dc7cffb6 ]
gue tunnels run iptunnel_pull_offloads on received skbs. This can
determine a possible use-after-free accessing guehdr pointer since
the packet will be 'uncloned' running pskb_expand_head if it is a
cloned gso skb (e.g if the packet has been sent though a veth device)
Fixes: a09a4c8dd1ec ("tunnels: Remove encapsulation offloads on decap")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/fou.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c index d83888bc33d3..b5a137338e50 100644 --- a/net/ipv4/fou.c +++ b/net/ipv4/fou.c @@ -116,6 +116,7 @@ static int gue_udp_recv(struct sock *sk, struct sk_buff *skb) struct guehdr *guehdr; void *data; u16 doffset = 0; + u8 proto_ctype; if (!fou) return 1; @@ -173,13 +174,14 @@ static int gue_udp_recv(struct sock *sk, struct sk_buff *skb) if (unlikely(guehdr->control)) return gue_control_message(skb, guehdr); + proto_ctype = guehdr->proto_ctype; __skb_pull(skb, sizeof(struct udphdr) + hdrlen); skb_reset_transport_header(skb); if (iptunnel_pull_offloads(skb)) goto drop; - return -guehdr->proto_ctype; + return -proto_ctype; drop: kfree_skb(skb); |