BUG: soft lockup in call_timer_fn

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syzbot

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Jan 11, 2020, 2:38:09 AM1/11/20
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Hello,

syzbot found the following crash on:

HEAD commit: b0cdffaa Linux 4.14.163
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11e1cb25e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=19269c071a1fe30
dashboard link: https://syzkaller.appspot.com/bug?extid=26c1121e8af8fbf2c167
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

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

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+26c112...@syzkaller.appspotmail.com

Dropped {multi|broad}cast of type= [86dd]
watchdog: BUG: soft lockup - CPU#1 stuck for 115s! [syz-executor.2:15753]
Modules linked in:
irq event stamp: 41311997
hardirqs last enabled at (41311996): [<ffffffff86800979>]
restore_regs_and_return_to_kernel+0x0/0x27
hardirqs last disabled at (41311997): [<ffffffff86801b01>]
apic_timer_interrupt+0x91/0xa0 arch/x86/entry/entry_64.S:792
softirqs last enabled at (18222080): [<ffffffff86a00645>]
__do_softirq+0x645/0x9a0 kernel/softirq.c:314
softirqs last disabled at (18227849): [<ffffffff81390620>] invoke_softirq
kernel/softirq.c:368 [inline]
softirqs last disabled at (18227849): [<ffffffff81390620>]
irq_exit+0x160/0x1b0 kernel/softirq.c:409
CPU: 1 PID: 15753 Comm: syz-executor.2 Not tainted 4.14.163-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
task: ffff888094394300 task.stack: ffff88804b270000
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779
[inline]
RIP: 0010:lock_acquire+0x1ea/0x430 kernel/locking/lockdep.c:3997
RSP: 0018:ffff8880aed07cf0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0fe2d29 RBX: ffff888094394300 RCX: 0000000002a75fde
RDX: dffffc0000000000 RSI: ffff888094394bd0 RDI: 0000000000000286
RBP: ffff8880aed07d38 R08: 0000000000006670 R09: ffffffff8959dd40
R10: ffff888094394bd0 R11: ffff888094394300 R12: ffff8880aed07d90
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007fe125cd2700(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c434a81000 CR3: 000000007ae2e000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
call_timer_fn+0x114/0x670 kernel/time/timer.c:1276
expire_timers kernel/time/timer.c:1318 [inline]
__run_timers kernel/time/timer.c:1636 [inline]
__run_timers kernel/time/timer.c:1604 [inline]
run_timer_softirq+0x5b7/0x1520 kernel/time/timer.c:1649
__do_softirq+0x244/0x9a0 kernel/softirq.c:288
invoke_softirq kernel/softirq.c:368 [inline]
irq_exit+0x160/0x1b0 kernel/softirq.c:409
exiting_irq arch/x86/include/asm/apic.h:648 [inline]
smp_apic_timer_interrupt+0x146/0x5e0 arch/x86/kernel/apic/apic.c:1102
apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792
</IRQ>
RIP: 0010:rcu_is_watching+0x7e/0xb0 kernel/rcu/tree.c:1131
RSP: 0018:ffff88804b2776f0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: 0000000000000001 RBX: ffff8880aed23940 RCX: 1ffffffff0f82dad
RDX: 0000000000000000 RSI: ffffffff87047d00 RDI: ffff8880aed2394c
RBP: ffff88804b277700 R08: 0000000000000000 R09: ffff888094394bc8
R10: ffff888094394ba8 R11: ffff888094394300 R12: ffffea00023bfc80
R13: dead000000000100 R14: ffffffffffffffff R15: ffffea00023bfcb8
rcu_read_unlock include/linux/rcupdate.h:681 [inline]
__unlock_page_memcg+0x78/0x100 mm/memcontrol.c:1716
unlock_page_memcg+0x2c/0x40 mm/memcontrol.c:1725
page_remove_file_rmap mm/rmap.c:1245 [inline]
page_remove_rmap+0x1c7/0x940 mm/rmap.c:1296
zap_pte_range mm/memory.c:1342 [inline]
zap_pmd_range mm/memory.c:1444 [inline]
zap_pud_range mm/memory.c:1473 [inline]
zap_p4d_range mm/memory.c:1494 [inline]
unmap_page_range+0xabd/0x19f0 mm/memory.c:1515
unmap_single_vma+0x15d/0x2c0 mm/memory.c:1560
unmap_vmas+0xac/0x170 mm/memory.c:1590
exit_mmap+0x285/0x4e0 mm/mmap.c:3056
__mmput kernel/fork.c:930 [inline]
mmput+0x114/0x440 kernel/fork.c:951
exit_mm kernel/exit.c:545 [inline]
do_exit+0x952/0x2cd0 kernel/exit.c:845
do_group_exit+0x111/0x330 kernel/exit.c:955
get_signal+0x381/0x1cd0 kernel/signal.c:2413
do_signal+0x86/0x19a0 arch/x86/kernel/signal.c:814
exit_to_usermode_loop+0x15c/0x220 arch/x86/entry/common.c:160
prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x414ce1
RSP: 002b:00007fe125cd17a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: 0000000000000004 RBX: 6666666666666667 RCX: 0000000000414ce1
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fe125cd1850
RBP: 000000000075bf20 R08: 000000000000000f R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00007fe125cd26d4
R13: 00000000004cc1c7 R14: 00000000004e6f20 R15: 00000000ffffffff
Code: 83 7c 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 f5 01 00 00
48 83 3d 9a f1 a8 06 00 0f 84 5e 01 00 00 48 8b 7d c8 57 9d <0f> 1f 44 00
00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 65
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7382 Comm: kworker/u4:5 Not tainted 4.14.163-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: writeback wb_workfn (flush-8:0)
task: ffff888055f8c300 task.stack: ffff888055f90000
RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline]
RIP: 0010:csd_lock_wait kernel/smp.c:108 [inline]
RIP: 0010:smp_call_function_single+0xfd/0x370 kernel/smp.c:302
RSP: 0018:ffff888055f96e60 EFLAGS: 00000297
RAX: ffff888055f8c300 RBX: 1ffff1100abf2dd0 RCX: 0000000000000830
RDX: 0000000000000000 RSI: 00000000000000fb RDI: 0000000000000830
RBP: ffff888055f96f08 R08: 0000000000004638 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff888055f97010 R14: 0000000000000000 R15: 0000000000000040
FS: 0000000000000000(0000) GS:ffff8880aec00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd89814f2b8 CR3: 0000000007e6a000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
smp_call_function_many+0x638/0x7c0 kernel/smp.c:434
native_flush_tlb_others+0x81/0x4a0 arch/x86/mm/tlb.c:663
flush_tlb_others arch/x86/include/asm/paravirt.h:309 [inline]
flush_tlb_mm_range+0x1ce/0x340 arch/x86/mm/tlb.c:712
flush_tlb_page arch/x86/include/asm/tlbflush.h:573 [inline]
ptep_clear_flush+0xe6/0x110 mm/pgtable-generic.c:87
page_mkclean_one+0x267/0x5c0 mm/rmap.c:915
rmap_walk_file+0x38d/0x8b0 mm/rmap.c:1829
rmap_walk+0xed/0x190 mm/rmap.c:1847
page_mkclean+0x162/0x1a0 mm/rmap.c:981
clear_page_dirty_for_io+0x1fb/0x7f0 mm/page-writeback.c:2704
mpage_submit_page+0x77/0x240 fs/ext4/inode.c:2202
mpage_process_page_bufs+0x418/0x510 fs/ext4/inode.c:2332
mpage_prepare_extent_to_map+0x489/0xb20 fs/ext4/inode.c:2704
ext4_writepages+0x105f/0x2fd0 fs/ext4/inode.c:2851
do_writepages+0xd0/0x250 mm/page-writeback.c:2361
__writeback_single_inode+0xe6/0x1120 fs/fs-writeback.c:1367
writeback_sb_inodes+0x4ce/0xeb0 fs/fs-writeback.c:1631
__writeback_inodes_wb+0xc3/0x210 fs/fs-writeback.c:1700
wb_writeback+0x735/0xba0 fs/fs-writeback.c:1809
wb_check_old_data_flush fs/fs-writeback.c:1922 [inline]
wb_do_writeback fs/fs-writeback.c:1946 [inline]
wb_workfn+0x943/0xf70 fs/fs-writeback.c:1975
process_one_work+0x863/0x1600 kernel/workqueue.c:2114
worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248
kthread+0x319/0x430 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Code: 13 09 00 48 8b 54 24 10 4c 89 e9 8b 7c 24 1c 48 8d 74 24 40 e8 d5 fa
ff ff 41 89 c4 8b 44 24 58 a8 01 74 10 e8 55 13 09 00 f3 90 <8b> 54 24 58
83 e2 01 75 f0 e8 45 13 09 00 e8 40 13 09 00 bf 01


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syzbot

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May 10, 2020, 3:38:06 AM5/10/20
to syzkaller...@googlegroups.com
Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.
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