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| author |   Taehee Yoo <ap420073@gmail.com> | 2018-05-17 22:49:49 +0900 |
|---|---|---|
| committer |   Pablo Neira Ayuso <pablo@netfilter.org> | 2018-05-23 09:29:05 +0200 |
| commit | 97a0549b15a0b466c47f6a0143a490a082c64b4e (patch) | |
| tree | 22910c45a0161744e71401a1a813400fc2b4067d /net | |
| parent | netfilter: ebtables: handle string from userspace with care (diff) | |
| download | linux-dev-97a0549b15a0b466c47f6a0143a490a082c64b4e.tar.xz linux-dev-97a0549b15a0b466c47f6a0143a490a082c64b4e.zip | |
netfilter: nft_meta: fix wrong value dereference in nft_meta_set_eval
In the nft_meta_set_eval, nftrace value is dereferenced as u32 from sreg.
But correct type is u8. so that sometimes incorrect value is dereferenced.
Steps to reproduce:
%nft add table ip filter
%nft add chain ip filter input { type filter hook input priority 4\; }
%nft add rule ip filter input nftrace set 0
%nft monitor
Sometimes, we can see trace messages.
trace id 16767227 ip filter input packet: iif "enp2s0"
ether saddr xx:xx:xx:xx:xx:xx ether daddr xx:xx:xx:xx:xx:xx
ip saddr 192.168.0.1 ip daddr 255.255.255.255 ip dscp cs0
ip ecn not-ect ip
trace id 16767227 ip filter input rule nftrace set 0 (verdict continue)
trace id 16767227 ip filter input verdict continue
trace id 16767227 ip filter input
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nft_meta.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c index 8fb91940e2e7..204af9899482 100644 --- a/net/netfilter/nft_meta.c +++ b/net/netfilter/nft_meta.c @@ -234,7 +234,7 @@ void nft_meta_set_eval(const struct nft_expr *expr, struct sk_buff *skb = pkt->skb; u32 *sreg = ®s->data[meta->sreg]; u32 value = *sreg; - u8 pkt_type; + u8 value8; switch (meta->key) { case NFT_META_MARK: @@ -244,15 +244,17 @@ void nft_meta_set_eval(const struct nft_expr *expr, skb->priority = value; break; case NFT_META_PKTTYPE: - pkt_type = nft_reg_load8(sreg); + value8 = nft_reg_load8(sreg); - if (skb->pkt_type != pkt_type && - skb_pkt_type_ok(pkt_type) && + if (skb->pkt_type != value8 && + skb_pkt_type_ok(value8) && skb_pkt_type_ok(skb->pkt_type)) - skb->pkt_type = pkt_type; + skb->pkt_type = value8; break; case NFT_META_NFTRACE: - skb->nf_trace = !!value; + value8 = nft_reg_load8(sreg); + + skb->nf_trace = !!value8; break; default: WARN_ON(1); |