diff options
| author | Florian Westphal <fw@strlen.de> | 2021-10-20 18:08:10 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2021-10-22 14:09:42 +0200 |
| commit | 5648b5e1169ff1d6d6a46c35c0b5fbebd2a5cbb2 (patch) | |
| tree | 7b5d8fb89ade113068f410b78630d10abd271c08 /net/netfilter/nfnetlink_queue.c | |
| parent | 64222515138e43da1fcf288f0289ef1020427b87 (diff) | |
netfilter: nfnetlink_queue: fix OOB when mac header was cleared
On 64bit platforms the MAC header is set to 0xffff on allocation and
also when a helper like skb_unset_mac_header() is called.
dev_parse_header may call skb_mac_header() which assumes valid mac offset:
BUG: KASAN: use-after-free in eth_header_parse+0x75/0x90
Read of size 6 at addr ffff8881075a5c05 by task nf-queue/1364
Call Trace:
memcpy+0x20/0x60
eth_header_parse+0x75/0x90
__nfqnl_enqueue_packet+0x1a61/0x3380
__nf_queue+0x597/0x1300
nf_queue+0xf/0x40
nf_hook_slow+0xed/0x190
nf_hook+0x184/0x440
ip_output+0x1c0/0x2a0
nf_reinject+0x26f/0x700
nfqnl_recv_verdict+0xa16/0x18b0
nfnetlink_rcv_msg+0x506/0xe70
The existing code only works if the skb has a mac header.
Fixes: 2c38de4c1f8da7 ("netfilter: fix looped (broad|multi)cast's MAC handling")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/nfnetlink_queue.c')
| -rw-r--r-- | net/netfilter/nfnetlink_queue.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 4c3fbaaeb103..4acc4b8e9fe5 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -560,7 +560,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, goto nla_put_failure; if (indev && entskb->dev && - entskb->mac_header != entskb->network_header) { + skb_mac_header_was_set(entskb)) { struct nfqnl_msg_packet_hw phw; int len; |