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| author | Miaohe Lin <linmiaohe@huawei.com> | 2020-08-15 11:44:31 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-08-27 10:31:47 +0300 |
| commit | a75f8a60c415325c7ce3df90bfe1b782f84b78cf (patch) | |
| tree | 8c49da6e3c7d743ce99b1c991735d0e41d35d195 | |
| parent | 3f13223bb0b19e978348e38be453ffa810017742 (diff) | |
| download | linux-a75f8a60c415325c7ce3df90bfe1b782f84b78cf.tar.xz | |
net: Fix potential wrong skb->protocol in skb_vlan_untag()
[ Upstream commit 55eff0eb7460c3d50716ed9eccf22257b046ca92 ]
We may access the two bytes after vlan_hdr in vlan_set_encap_proto(). So
we should pull VLAN_HLEN + sizeof(unsigned short) in skb_vlan_untag() or
we may access the wrong data.
Fixes: 0d5501c1c828 ("net: Always untag vlan-tagged traffic on input.")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/core/skbuff.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index b8afefe6f6b6..7afe52bd038b 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5419,8 +5419,8 @@ struct sk_buff *skb_vlan_untag(struct sk_buff *skb) skb = skb_share_check(skb, GFP_ATOMIC); if (unlikely(!skb)) goto err_free; - - if (unlikely(!pskb_may_pull(skb, VLAN_HLEN))) + /* We may access the two bytes after vlan_hdr in vlan_set_encap_proto(). */ + if (unlikely(!pskb_may_pull(skb, VLAN_HLEN + sizeof(unsigned short)))) goto err_free; vhdr = (struct vlan_hdr *)skb->data; |