[syzbot] [net?] WARNING in xfrm_policy_fini (2)

[syzbot] [net?] WARNING in xfrm_policy_fini (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    e28531143b25 net: ethernet: mtk_eth_soc: mtk_ppe: prefer n..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=163c0ac5c80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a3bc1f699d6e9cb0
dashboard link: https://syzkaller.appspot.com/bug?extid=b3346cca0c23c839e787
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6ff439efecb6/disk-e2853114.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/280d508d228c/vmlinux-e2853114.xz
kernel image: https://storage.googleapis.com/syzbot-assets/af98eb5ab0e4/bzImage-e2853114.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b3346cca0c23c839e787@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 41 at net/xfrm/xfrm_policy.c:4176 xfrm_policy_fini+0x2f2/0x3c0 net/xfrm/xfrm_policy.c:4176
Modules linked in:
CPU: 0 PID: 41 Comm: kworker/u4:2 Not tainted 6.3.0-rc5-syzkaller-01242-ge28531143b25 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
Workqueue: netns cleanup_net
RIP: 0010:xfrm_policy_fini+0x2f2/0x3c0 net/xfrm/xfrm_policy.c:4176
Code: cd f8 0f 0b 8b 74 24 04 e9 56 fe ff ff e8 a6 a1 cd f8 0f 0b e9 e1 fd ff ff e8 9a a1 cd f8 0f 0b e9 02 ff ff ff e8 8e a1 cd f8 <0f> 0b e9 76 fd ff ff e8 d2 ea 1e f9 e9 8d fe ff ff 48 89 ef e8 e5
RSP: 0018:ffffc90000b27bd8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88807945b980 RCX: 0000000000000000
RDX: ffff8880177b57c0 RSI: ffffffff88b53632 RDI: 0000000000000000
RBP: ffff88807945cd00 R08: 0000000000000001 R09: ffffffff914e0b8f
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8e28cb40
R13: ffffc90000b27ca0 R14: dffffc0000000000 R15: fffffbfff1c5196c
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f60f8cb7378 CR3: 000000000c571000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 xfrm_net_exit+0x1d/0x60 net/xfrm/xfrm_policy.c:4240
 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:169
 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:613
 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390
 worker_thread+0x669/0x1090 kernel/workqueue.c:2537
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>


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Re: [syzbot] [net?] WARNING in xfrm_policy_fini (2)

[Herbert Xu]

On Tue, Apr 11, 2023 at 05:22:53PM -0700, syzbot wrote:
>
> WARNING: CPU: 0 PID: 41 at net/xfrm/xfrm_policy.c:4176 xfrm_policy_fini+0x2f2/0x3c0 net/xfrm/xfrm_policy.c:4176

This code was broken from day one.  Prior to netns this policy
fini function didn't exist.

With netns, somehow it wants to get rid of all xfrm policies.
However, it's not doing a very good job at it because it only
deletes the global policies, and not the socket policies.

Therefore this is completely expected to fail.

Do we have a netns maintainer? What is this supposed to do?

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt