diff options
| author |   Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr> | 2021-12-10 16:31:27 +0100 |
|---|---|---|
| committer |   Pablo Neira Ayuso <pablo@netfilter.org> | 2021-12-16 00:06:24 +0100 |
| commit | ebb966d3bdfed581ecccbb4a7432341baf7619b4 (patch) | |
| tree | 769b61302917f9342b3379a2376be2ebc93792e9 | |
| parent | netfilter: nf_tables: fix use-after-free in nft_set_catchall_destroy() (diff) | |
| download | linux-dev-ebb966d3bdfed581ecccbb4a7432341baf7619b4.tar.xz linux-dev-ebb966d3bdfed581ecccbb4a7432341baf7619b4.zip | |
netfilter: fix regression in looped (broad|multi)cast's MAC handling
In commit 5648b5e1169f ("netfilter: nfnetlink_queue: fix OOB when mac
header was cleared"), the test for non-empty MAC header introduced in
commit 2c38de4c1f8da7 ("netfilter: fix looped (broad|multi)cast's MAC
handling") has been replaced with a test for a set MAC header.
This breaks the case when the MAC header has been reset (using
skb_reset_mac_header), as is the case with looped-back multicast
packets. As a result, the packets ending up in NFQUEUE get a bogus
hwaddr interpreted from the first bytes of the IP header.
This patch adds a test for a non-empty MAC header in addition to the
test for a set MAC header. The same two tests are also implemented in
nfnetlink_log.c, where the initial code of commit 2c38de4c1f8da7
("netfilter: fix looped (broad|multi)cast's MAC handling") has not been
touched, but where supposedly the same situation may happen.
Fixes: 5648b5e1169f ("netfilter: nfnetlink_queue: fix OOB when mac header was cleared")
Signed-off-by: Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| -rw-r--r-- | net/netfilter/nfnetlink_log.c | 3 | ||||
| -rw-r--r-- | net/netfilter/nfnetlink_queue.c | 3 |
2 files changed, 4 insertions, 2 deletions
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index 691ef4cffdd9..7f83f9697fc1 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -556,7 +556,8 @@ __build_packet_message(struct nfnl_log_net *log, goto nla_put_failure; if (indev && skb->dev && - skb->mac_header != skb->network_header) { + skb_mac_header_was_set(skb) && + skb_mac_header_len(skb) != 0) { struct nfulnl_msg_packet_hw phw; int len; diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 5837e8efc9c2..f0b9e21a2452 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -560,7 +560,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, goto nla_put_failure; if (indev && entskb->dev && - skb_mac_header_was_set(entskb)) { + skb_mac_header_was_set(entskb) && + skb_mac_header_len(entskb) != 0) { struct nfqnl_msg_packet_hw phw; int len; |