BUG: soft lockup in tipc_topsrv_accept

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14c3139eb00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=43daa75862aa700d7de0
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

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+43daa7...@syzkaller.appspotmail.com

IPVS: ftp: loaded support on port[0] = 21
EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue
watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [kworker/u4:4:2895]
Modules linked in:
irq event stamp: 125364999
hardirqs last enabled at (125364998): [<ffffffff8129070b>] kvm_wait arch/x86/kernel/kvm.c:799 [inline]
hardirqs last enabled at (125364998): [<ffffffff8129070b>] kvm_wait+0x14b/0x240 arch/x86/kernel/kvm.c:779
hardirqs last disabled at (125364999): [<ffffffff81003d00>] trace_hardirqs_off_thunk+0x1a/0x1c
softirqs last enabled at (125345382): [<ffffffff87ba4ea3>] tipc_accept+0x213/0x10b0 net/tipc/socket.c:2566
softirqs last disabled at (125345394): [<ffffffff87bb0939>] spin_lock_bh include/linux/spinlock.h:334 [inline]
softirqs last disabled at (125345394): [<ffffffff87bb0939>] tipc_conn_alloc+0x319/0x4f0 net/tipc/topsrv.c:204
CPU: 0 PID: 2895 Comm: kworker/u4:4 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: tipc_rcv tipc_topsrv_accept
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: 48 89 df e8 f4 20 7f f9 e9 2e ff ff ff 48 89 df e8 e7 20 7f f9 eb 82 90 90 90 90 90 e9 07 00 00 00 0f 00 2d 14 43 4e 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d 04 43 4e 00 f4 c3 90 90 41 56 41 55
RSP: 0018:ffff8880abc9fb30 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff13e3054 RBX: ffff888097fb47d0 RCX: 1ffff11015792957
RDX: dffffc0000000000 RSI: ffff8880abc94a98 RDI: ffff8880abc94a44
RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000286
R13: ffffed1012ff68fa R14: 0000000000000001 R15: ffff8880ba02be00
FS: 0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000559a39ec56e0 CR3: 00000000547c3000 CR4: 00000000003426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
kvm_wait arch/x86/kernel/kvm.c:799 [inline]
kvm_wait+0x179/0x240 arch/x86/kernel/kvm.c:779
pv_wait arch/x86/include/asm/paravirt.h:689 [inline]
pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:471 [inline]
__pv_queued_spin_lock_slowpath+0x86a/0xae0 kernel/locking/qspinlock.c:474
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:679 [inline]
queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:53 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:88 [inline]
do_raw_spin_lock+0x189/0x220 kernel/locking/spinlock_debug.c:113
spin_lock_bh include/linux/spinlock.h:334 [inline]
tipc_conn_alloc+0x319/0x4f0 net/tipc/topsrv.c:204
tipc_topsrv_accept+0x1b5/0x280 net/tipc/topsrv.c:470
process_one_work+0x864/0x1570 kernel/workqueue.c:2153
worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 23 Comm: kworker/u4:1 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:23 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:67 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0xd/0x50 kernel/kcov.c:101
Code: ff 4c 89 ef e8 04 dd 35 00 e9 23 fe ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 34 24 65 48 8b 04 25 c0 df 01 00 <65> 8b 15 cc 59 9f 7e 81 e2 00 01 1f 00 75 2b 8b 90 60 13 00 00 83
RSP: 0018:ffff8880b5047b60 EFLAGS: 00000282
RAX: ffff8880b503c600 RBX: 0000000028b269cd RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff87eef291 RDI: ffff888097fb4780
RBP: ffff888097fb4780 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000040
R13: ffffed1012ff6901 R14: dffffc0000000000 R15: 0000000000000176
FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055fc12e95a40 CR3: 000000004da19000 CR4: 00000000003426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__read_once_size include/linux/compiler.h:263 [inline]
radix_tree_load_root lib/radix-tree.c:603 [inline]
__radix_tree_lookup+0x51/0x370 lib/radix-tree.c:1040
tipc_topsrv_stop net/tipc/topsrv.c:698 [inline]
tipc_topsrv_exit_net+0x25e/0x5c0 net/tipc/topsrv.c:722
ops_exit_list+0xa5/0x150 net/core/net_namespace.c:153
cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:554
process_one_work+0x864/0x1570 kernel/workqueue.c:2153
worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
----------------
Code disassembly (best guess):
0: 48 89 df mov %rbx,%rdi
3: e8 f4 20 7f f9 callq 0xf97f20fc
8: e9 2e ff ff ff jmpq 0xffffff3b
d: 48 89 df mov %rbx,%rdi
10: e8 e7 20 7f f9 callq 0xf97f20fc
15: eb 82 jmp 0xffffff99
17: 90 nop
18: 90 nop
19: 90 nop
1a: 90 nop
1b: 90 nop
1c: e9 07 00 00 00 jmpq 0x28
21: 0f 00 2d 14 43 4e 00 verw 0x4e4314(%rip) # 0x4e433c
28: fb sti
29: f4 hlt
* 2a: c3 retq <-- trapping instruction
2b: 90 nop
2c: e9 07 00 00 00 jmpq 0x38
31: 0f 00 2d 04 43 4e 00 verw 0x4e4304(%rip) # 0x4e433c
38: f4 hlt
39: c3 retq
3a: 90 nop
3b: 90 nop
3c: 41 56 push %r14
3e: 41 55 push %r13


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[syzbot]

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