| Message ID | 20230111212251.193032-4-pablo@netfilter.org |
|---|---|
| State | Superseded |
| Delegated to: | Pablo Neira |
| Headers | show |
| Series | [net,1/3] selftests: netfilter: fix transaction test script timeout handling | expand |
diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index 17b418a5a593..3a3c7746e88f 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);
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> --- net/netfilter/nft_payload.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)