| Message ID | 20240513102751.16105-1-fw@strlen.de (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [nf] netfilter: tproxy: bail out if IP has been disabled on the device | expand |
diff --git a/net/ipv4/netfilter/nf_tproxy_ipv4.c b/net/ipv4/netfilter/nf_tproxy_ipv4.c index 69e331799604..73e66a088e25 100644 --- a/net/ipv4/netfilter/nf_tproxy_ipv4.c +++ b/net/ipv4/netfilter/nf_tproxy_ipv4.c @@ -58,6 +58,8 @@ __be32 nf_tproxy_laddr4(struct sk_buff *skb, __be32 user_laddr, __be32 daddr) laddr = 0; indev = __in_dev_get_rcu(skb->dev); + if (!indev) + return daddr; in_dev_for_each_ifa_rcu(ifa, indev) { if (ifa->ifa_flags & IFA_F_SECONDARY)
syzbot reports: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] [..] RIP: 0010:nf_tproxy_laddr4+0xb7/0x340 net/ipv4/netfilter/nf_tproxy_ipv4.c:62 Call Trace: nft_tproxy_eval_v4 net/netfilter/nft_tproxy.c:56 [inline] nft_tproxy_eval+0xa9a/0x1a00 net/netfilter/nft_tproxy.c:168 __in_dev_get_rcu() can return NULL, so check for this. Reported-and-tested-by: syzbot+b94a6818504ea90d7661@syzkaller.appspotmail.com Fixes: cc6eb4338569 ("tproxy: use the interface primary IP address as a default value for --on-ip") Signed-off-by: Florian Westphal <fw@strlen.de> --- net/ipv4/netfilter/nf_tproxy_ipv4.c | 2 ++ 1 file changed, 2 insertions(+)