From: Steffen Klassert <steffen.klassert@secunet.com>
To: Florian Westphal <fw@strlen.de>
Cc: <netdev@vger.kernel.org>, <syzkaller-bugs@googlegroups.com>,
<syzbot+8cc27ace5f6972910b31@syzkaller.appspotmail.com>
Subject: Re: [PATCH ipsec] xfrm: policy: avoid warning splat when merging nodes
Date: Wed, 21 Aug 2019 08:41:30 +0200 [thread overview]
Message-ID: <20190821064130.GN2879@gauss3.secunet.de> (raw)
In-Reply-To: <20190812083213.5010-1-fw@strlen.de>
On Mon, Aug 12, 2019 at 10:32:13AM +0200, Florian Westphal wrote:
> syzbot reported a splat:
> xfrm_policy_inexact_list_reinsert+0x625/0x6e0 net/xfrm/xfrm_policy.c:877
> CPU: 1 PID: 6756 Comm: syz-executor.1 Not tainted 5.3.0-rc2+ #57
> Call Trace:
> xfrm_policy_inexact_node_reinsert net/xfrm/xfrm_policy.c:922 [inline]
> xfrm_policy_inexact_node_merge net/xfrm/xfrm_policy.c:958 [inline]
> xfrm_policy_inexact_insert_node+0x537/0xb50 net/xfrm/xfrm_policy.c:1023
> xfrm_policy_inexact_alloc_chain+0x62b/0xbd0 net/xfrm/xfrm_policy.c:1139
> xfrm_policy_inexact_insert+0xe8/0x1540 net/xfrm/xfrm_policy.c:1182
> xfrm_policy_insert+0xdf/0xce0 net/xfrm/xfrm_policy.c:1574
> xfrm_add_policy+0x4cf/0x9b0 net/xfrm/xfrm_user.c:1670
> xfrm_user_rcv_msg+0x46b/0x720 net/xfrm/xfrm_user.c:2676
> netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2477
> xfrm_netlink_rcv+0x74/0x90 net/xfrm/xfrm_user.c:2684
> netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
> netlink_unicast+0x809/0x9a0 net/netlink/af_netlink.c:1328
> netlink_sendmsg+0xa70/0xd30 net/netlink/af_netlink.c:1917
> sock_sendmsg_nosec net/socket.c:637 [inline]
> sock_sendmsg net/socket.c:657 [inline]
>
> There is no reproducer, however, the warning can be reproduced
> by adding rules with ever smaller prefixes.
>
> The sanity check ("does the policy match the node") uses the prefix value
> of the node before its updated to the smaller value.
>
> To fix this, update the prefix earlier. The bug has no impact on tree
> correctness, this is only to prevent a false warning.
>
> Reported-by: syzbot+8cc27ace5f6972910b31@syzkaller.appspotmail.com
> Signed-off-by: Florian Westphal <fw@strlen.de>
Applied, thanks Florian!
prev parent reply other threads:[~2019-08-21 6:41 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-08 16:45 WARNING in xfrm_policy_inexact_list_reinsert syzbot
2019-08-12 8:32 ` [PATCH ipsec] xfrm: policy: avoid warning splat when merging nodes Florian Westphal
2019-08-21 6:41 ` Steffen Klassert [this message]
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