diff options
| author | Pablo Neira Ayuso | 2023-01-11 17:07:33 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-01-18 11:58:09 +0100 |
| commit | 76ef74d4a379faa451003621a84e3498044e7aa3 (patch) | |
| tree | 05fb4ad2ea5f61e5842ed2d7ba4cee20b0b1c398 /net | |
| parent | 38f3ee12661fdc2805e06942e4e3d604e03cd9cf (diff) | |
netfilter: nft_payload: incorrect arithmetics when fetching VLAN header bits
commit 696e1a48b1a1b01edad542a1ef293665864a4dd0 upstream.
If the offset + length goes over the ethernet + vlan header, then the
length is adjusted to copy the bytes that are within the boundaries of
the vlan_ethhdr scratchpad area. The remaining bytes beyond ethernet +
vlan header are copied directly from the skbuff data area.
Fix incorrect arithmetic operator: subtract, not add, the size of the
vlan header in case of double-tagged packets to adjust the length
accordingly to address CVE-2023-0179.
Reported-by: Davide Ornaghi <d.ornaghi97@gmail.com>
Fixes: f6ae9f120dad ("netfilter: nft_payload: add C-VLAN support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nft_payload.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index 4edd899aeb9b..d7de2ecb287e 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -62,7 +62,7 @@ nft_payload_copy_vlan(u32 *d, const struct sk_buff *skb, u8 offset, u8 len) return false; if (offset + len > VLAN_ETH_HLEN + vlan_hlen) - ethlen -= offset + len - VLAN_ETH_HLEN + vlan_hlen; + ethlen -= offset + len - VLAN_ETH_HLEN - vlan_hlen; memcpy(dst_u8, vlanh + offset - vlan_hlen, ethlen); |