diff options
| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2023-01-11 17:07:33 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2023-01-11 19:18:04 +0100 |
| commit | 696e1a48b1a1b01edad542a1ef293665864a4dd0 (patch) | |
| tree | 6c6cd112a0f4e9b772306843c67443020f492fd8 /net/netfilter/nft_payload.c | |
| parent | 9ea4b476cea1b7d461d16dda25ca3c7e616e2d15 (diff) | |
| download | linux-696e1a48b1a1b01edad542a1ef293665864a4dd0.tar.gz | |
netfilter: nft_payload: incorrect arithmetics when fetching VLAN header bits
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>
Diffstat (limited to 'net/netfilter/nft_payload.c')
| -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 17b418a5a593af..3a3c7746e88fe6 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -63,7 +63,7 @@ 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); |