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Draft: CVE-2024-36270: netfilter: tproxy: bail out if IP has been disabled on the device

CKI Backport Bot requested to merge redhat/red-hat-ci-tools/kernel/bot-branches/centos-stream-9:backport-RHEL-44369-centos-stream-9-main into main

JIRA: https://issues.redhat.com/browse/RHEL-44369
CVE: CVE-2024-36270

netfilter: tproxy: bail out if IP has been disabled on the device

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>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
(cherry picked from commit 21a673bddc8fd4873c370caf9ae70ffc6d47e8d3)

Signed-off-by: cki-backport-bot cki-ci-bot+cki-gitlab-backport-bot@redhat.com

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