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| author | Florian Westphal <fw@strlen.de> | 2023-09-29 10:42:10 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-06-12 11:03:57 +0200 |
| commit | cffee0b578ba6655bbb851c486e9c2003c91ad12 (patch) | |
| tree | c858ac27954400dbb83eae5dac943159a407843d /net | |
| parent | 96f261d56c2d2433d9890e07afe8e9b8a214f141 (diff) | |
| download | linux-cffee0b578ba6655bbb851c486e9c2003c91ad12.tar.gz linux-cffee0b578ba6655bbb851c486e9c2003c91ad12.tar.bz2 linux-cffee0b578ba6655bbb851c486e9c2003c91ad12.zip | |
netfilter: nft_payload: rebuild vlan header on h_proto access
[ Upstream commit af84f9e447a65b4b9f79e7e5d69e19039b431c56 ]
nft can perform merging of adjacent payload requests.
This means that:
ether saddr 00:11 ... ether type 8021ad ...
is a single payload expression, for 8 bytes, starting at the
ethernet source offset.
Check that offset+length is fully within the source/destination mac
addersses.
This bug prevents 'ether type' from matching the correct h_proto in case
vlan tag got stripped.
Fixes: de6843be3082 ("netfilter: nft_payload: rebuild vlan header when needed")
Reported-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: Florian Westphal <fw@strlen.de>
Stable-dep-of: 33c563ebf8d3 ("netfilter: nft_payload: skbuff vlan metadata mangle support")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nft_payload.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index 74777a687eb5..eaa629c6d7da 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -109,6 +109,17 @@ static int nft_payload_inner_offset(const struct nft_pktinfo *pkt) return pkt->inneroff; } +static bool nft_payload_need_vlan_copy(const struct nft_payload *priv) +{ + unsigned int len = priv->offset + priv->len; + + /* data past ether src/dst requested, copy needed */ + if (len > offsetof(struct ethhdr, h_proto)) + return true; + + return false; +} + void nft_payload_eval(const struct nft_expr *expr, struct nft_regs *regs, const struct nft_pktinfo *pkt) @@ -127,7 +138,7 @@ void nft_payload_eval(const struct nft_expr *expr, goto err; if (skb_vlan_tag_present(skb) && - priv->offset >= offsetof(struct ethhdr, h_proto)) { + nft_payload_need_vlan_copy(priv)) { if (!nft_payload_copy_vlan(dest, skb, priv->offset, priv->len)) goto err; |