diff mbox series

[net,7/7] netfilter: nft_payload: fix wrong mac header matching

Message ID 20231012085724.15155-8-fw@strlen.de (mailing list archive)
State Accepted
Commit d351c1ea2de3e36e608fc355d8ae7d0cc80e6cd6
Delegated to: Netdev Maintainers
Headers show
Series [net,1/7] netfilter: nf_tables: do not remove elements if set backend implements .abort | expand

Checks

Context Check Description
netdev/series_format success Pull request is its own cover letter
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1363 this patch: 1363
netdev/cc_maintainers fail 2 blamed authors not CCed: pablo@netfilter.org kaber@trash.net; 4 maintainers not CCed: kadlec@netfilter.org coreteam@netfilter.org pablo@netfilter.org kaber@trash.net
netdev/build_clang success Errors and warnings before: 1387 this patch: 1387
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 1387 this patch: 1387
netdev/checkpatch warning WARNING: line length of 81 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Florian Westphal Oct. 12, 2023, 8:57 a.m. UTC
mcast packets get looped back to the local machine.
Such packets have a 0-length mac header, we should treat
this like "mac header not set" and abort rule evaluation.

As-is, we just copy data from the network header instead.

Fixes: 96518518cc41 ("netfilter: add nftables")
Reported-by: Blažej Krajňák <krajnak@levonet.sk>
Signed-off-by: Florian Westphal <fw@strlen.de>
---
 net/netfilter/nft_payload.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c
index 120f6d395b98..0a689c8e0295 100644
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -179,7 +179,7 @@  void nft_payload_eval(const struct nft_expr *expr,
 
 	switch (priv->base) {
 	case NFT_PAYLOAD_LL_HEADER:
-		if (!skb_mac_header_was_set(skb))
+		if (!skb_mac_header_was_set(skb) || skb_mac_header_len(skb) == 0)
 			goto err;
 
 		if (skb_vlan_tag_present(skb) &&