This is a note to let you know that I've just added the patch titled
netfilter: tproxy: bail out if IP has been disabled on the device
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
netfilter-tproxy-bail-out-if-ip-has-been-disabled-on.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d926d0f3f6dc4fbd7fa506ea3db7be0af6dcf2f0
Author: Florian Westphal <fw@xxxxxxxxx>
Date: Mon May 13 12:27:15 2024 +0200
netfilter: tproxy: bail out if IP has been disabled on the device
[ Upstream commit 21a673bddc8fd4873c370caf9ae70ffc6d47e8d3 ]
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@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: cc6eb4338569 ("tproxy: use the interface primary IP address as a default value for --on-ip")
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv4/netfilter/nf_tproxy_ipv4.c b/net/ipv4/netfilter/nf_tproxy_ipv4.c
index 61cb2341f50fe..7c1a0cd9f4359 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)
