general protection fault in idr_get_next_ul

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: f6d5cb9e Linux 4.19.142
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13819285900000
kernel config: https://syzkaller.appspot.com/x/.config?x=30067df04d3254aa
dashboard link: https://syzkaller.appspot.com/bug?extid=c2d332a968393c559798
compiler: gcc (GCC) 10.1.0-syz 20200507

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c2d332...@syzkaller.appspotmail.com

IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 16211 Comm: kworker/u4:1 Not tainted 4.19.142-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:idr_get_next_ul+0x8b/0x350 lib/idr.c:235
Code: c7 40 0c f3 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 84 24 b0 00 00 00 31 c0 e8 80 0c 33 fa 49 8d 7e 48 48 89 f8 48 c1 e8 03 <0f> b6 04 28 84 c0 74 08 3c 03 0f 8e 69 02 00 00 48 89 da 41 8b 6e
RSP: 0018:ffff8880137d7a50 EFLAGS: 00010202
RAX: 0000ee00000000fe RBX: ffff8880137d7b70 RCX: 1ffff11009c54945
RDX: 0000000000000000 RSI: ffffffff8736a500 RDI: 00077000000007f0
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000004
R10: 0000000000000000 R11: 0000000000000000 R12: 00077000000007a8
R13: 0000000000077000 R14: 00077000000007a8 R15: 000000000000ee06
FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc928000000 CR3: 000000008e176000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
tcf_idrinfo_destroy+0xe5/0x1b0 net/sched/act_api.c:491
tc_action_net_exit include/net/act_api.h:139 [inline]
vlan_exit_net+0x16a/0x360 net/sched/act_vlan.c:332
ops_exit_list+0xf9/0x150 net/core/net_namespace.c:156
cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:553
process_one_work+0x864/0x1570 kernel/workqueue.c:2155
worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Modules linked in:
---[ end trace 15dcafe3f810ecf3 ]---
RIP: 0010:idr_get_next_ul+0x8b/0x350 lib/idr.c:235
Code: c7 40 0c f3 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 84 24 b0 00 00 00 31 c0 e8 80 0c 33 fa 49 8d 7e 48 48 89 f8 48 c1 e8 03 <0f> b6 04 28 84 c0 74 08 3c 03 0f 8e 69 02 00 00 48 89 da 41 8b 6e
RSP: 0018:ffff8880137d7a50 EFLAGS: 00010202
RAX: 0000ee00000000fe RBX: ffff8880137d7b70 RCX: 1ffff11009c54945
RDX: 0000000000000000 RSI: ffffffff8736a500 RDI: 00077000000007f0
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000004
R10: 0000000000000000 R11: 0000000000000000 R12: 00077000000007a8
R13: 0000000000077000 R14: 00077000000007a8 R15: 000000000000ee06
FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000007454d8 CR3: 0000000089db1000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.