syzbot
INFO: task hung in start_this_handle
Status:
upstream: reported on 2026/08/07 16:33
Reported-by: syzbot+7b3ea8ddd5b28ce98c93@syzkaller.appspotmail.com
First crash: 64d, last: 7d06h
Sample crash report:
INFO: task kworker/u4:12:3547 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:12 state:D stack:22056 pid:3547 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
add_transaction_credits fs/jbd2/transaction.c:300 [inline]
start_this_handle+0x103f/0x2170 fs/jbd2/transaction.c:407
jbd2__journal_start+0x2bb/0x5b0 fs/jbd2/transaction.c:505
__ext4_journal_start_sb+0x203/0x560 fs/ext4/ext4_jbd2.c:112
__ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline]
ext4_do_writepages+0xfb9/0x3990 fs/ext4/inode.c:2716
ext4_writepages+0x1dd/0x350 fs/ext4/inode.c:2822
do_writepages+0x351/0x590 mm/page-writeback.c:2575
__writeback_single_inode+0x14e/0xee0 fs/fs-writeback.c:1701
writeback_sb_inodes+0x813/0x1020 fs/fs-writeback.c:1992
wb_writeback+0x45e/0xbe0 fs/fs-writeback.c:2171
wb_do_writeback fs/fs-writeback.c:2318 [inline]
wb_workfn+0x400/0xe60 fs/fs-writeback.c:2358
process_one_work kernel/workqueue.c:2657 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
INFO: task syz-executor:5764 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22064 pid:5764 ppid:5763 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
io_schedule+0x80/0xd0 kernel/sched/core.c:9024
bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:209
__wait_on_bit+0x9f/0x2c0 kernel/sched/wait_bit.c:49
out_of_line_wait_on_bit+0x13c/0x190 kernel/sched/wait_bit.c:64
wait_on_bit_io include/linux/wait_bit.h:101 [inline]
do_get_write_access+0x5c9/0xe00 fs/jbd2/transaction.c:1096
jbd2_journal_get_write_access+0x10c/0x140 fs/jbd2/transaction.c:1231
__ext4_journal_get_write_access+0x208/0x6d0 fs/ext4/ext4_jbd2.c:241
ext4_reserve_inode_write+0x205/0x2a0 fs/ext4/inode.c:5945
__ext4_mark_inode_dirty+0x13f/0x720 fs/ext4/inode.c:6129
ext4_dirty_inode+0xcb/0x110 fs/ext4/inode.c:6166
__mark_inode_dirty+0x2cc/0xc90 fs/fs-writeback.c:2537
generic_update_time fs/inode.c:1981 [inline]
inode_update_time fs/inode.c:1994 [inline]
__file_update_time fs/inode.c:2180 [inline]
file_update_time+0x187/0x1a0 fs/inode.c:2210
ext4_page_mkwrite+0x1f9/0x11a0 fs/ext4/inode.c:6284
do_page_mkwrite+0x153/0x3f0 mm/memory.c:2951
wp_page_shared mm/memory.c:3311 [inline]
do_wp_page+0xd4d/0x34d0 mm/memory.c:3396
handle_pte_fault mm/memory.c:5063 [inline]
__handle_mm_fault mm/memory.c:5188 [inline]
handle_mm_fault+0x1306/0x4a50 mm/memory.c:5353
do_user_addr_fault+0x736/0x12d0 arch/x86/mm/fault.c:1371
handle_page_fault arch/x86/mm/fault.c:1463 [inline]
exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f0154e7c6e2
RSP: 002b:00007ffd3f7883c0 EFLAGS: 00010202
RAX: 00007f0152cc4000 RBX: 0000555591acf100 RCX: 0000000000000006
RDX: 0000000000003da6 RSI: 0000555591acdcc8 RDI: 0000000000000040
RBP: 00007ffd3f7888c0 R08: 0000555591acdcc8 R09: 0000000000000090
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffd3f788700
R13: 00007ffd3f7884f0 R14: 585858582e7a7973 R15: 00007ffd3f788440
</TASK>
INFO: task syz.0.71:6010 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.71 state:D stack:28464 pid:6010 ppid:5777 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
wb_wait_for_completion+0x173/0x2a0 fs/fs-writeback.c:192
sync_inodes_sb+0x1c9/0xa10 fs/fs-writeback.c:2844
iterate_supers+0xb2/0x170 fs/super.c:979
ksys_sync+0xa1/0x170 fs/sync.c:102
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4fdd59e159
RSP: 002b:00007f4fde3a1028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f4fdd826090 RCX: 00007f4fdd59e159
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f4fdd826090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4fdd826128 R14: 00007f4fdd826090 R15: 00007ffeb1a76658
</TASK>
INFO: task syz.3.91:6046 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.91 state:D stack:27048 pid:6046 ppid:5778 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
io_schedule+0x80/0xd0 kernel/sched/core.c:9024
bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:209
__wait_on_bit+0x9f/0x2c0 kernel/sched/wait_bit.c:49
out_of_line_wait_on_bit+0x13c/0x190 kernel/sched/wait_bit.c:64
wait_on_bit_io include/linux/wait_bit.h:101 [inline]
do_get_write_access+0x5c9/0xe00 fs/jbd2/transaction.c:1096
jbd2_journal_get_write_access+0x10c/0x140 fs/jbd2/transaction.c:1231
__ext4_journal_get_write_access+0x208/0x6d0 fs/ext4/ext4_jbd2.c:241
ext4_reserve_inode_write+0x205/0x2a0 fs/ext4/inode.c:5945
__ext4_mark_inode_dirty+0x13f/0x720 fs/ext4/inode.c:6129
ext4_dirty_inode+0xcb/0x110 fs/ext4/inode.c:6166
__mark_inode_dirty+0x2cc/0xc90 fs/fs-writeback.c:2537
generic_update_time fs/inode.c:1981 [inline]
inode_update_time fs/inode.c:1994 [inline]
__file_update_time fs/inode.c:2180 [inline]
file_update_time+0x187/0x1a0 fs/inode.c:2210
ext4_page_mkwrite+0x1f9/0x11a0 fs/ext4/inode.c:6284
do_page_mkwrite+0x153/0x3f0 mm/memory.c:2951
do_shared_fault mm/memory.c:4717 [inline]
do_fault mm/memory.c:4779 [inline]
do_pte_missing mm/memory.c:3689 [inline]
handle_pte_fault mm/memory.c:5047 [inline]
__handle_mm_fault mm/memory.c:5188 [inline]
handle_mm_fault+0x1a2c/0x4a50 mm/memory.c:5353
do_user_addr_fault+0x736/0x12d0 arch/x86/mm/fault.c:1371
handle_page_fault arch/x86/mm/fault.c:1463 [inline]
exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f5a2b472809
RSP: 002b:00007fff591334f0 EFLAGS: 00010202
RAX: 0000001b2e124000 RBX: 0000000000000000 RCX: 00000000005ffde8
RDX: 0000001b2e123ffc RSI: 00000000005ffde8 RDI: 00007f5a2c355700
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f5a2b812000
R10: 00007f5a2c355700 R11: 0000000000000000 R12: 0000000000000000
R13: 000000000001086b R14: ffffffff8132211e R15: 00007f5a2c355720
</TASK>
INFO: task syz.1.92:6049 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.92 state:D stack:25384 pid:6049 ppid:5776 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
io_schedule+0x80/0xd0 kernel/sched/core.c:9024
bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:209
__wait_on_bit+0x9f/0x2c0 kernel/sched/wait_bit.c:49
out_of_line_wait_on_bit+0x13c/0x190 kernel/sched/wait_bit.c:64
wait_on_bit_io include/linux/wait_bit.h:101 [inline]
do_get_write_access+0x5c9/0xe00 fs/jbd2/transaction.c:1096
jbd2_journal_get_write_access+0x10c/0x140 fs/jbd2/transaction.c:1231
__ext4_journal_get_write_access+0x208/0x6d0 fs/ext4/ext4_jbd2.c:241
ext4_reserve_inode_write+0x205/0x2a0 fs/ext4/inode.c:5945
__ext4_mark_inode_dirty+0x13f/0x720 fs/ext4/inode.c:6129
ext4_dirty_inode+0xcb/0x110 fs/ext4/inode.c:6166
__mark_inode_dirty+0x2cc/0xc90 fs/fs-writeback.c:2537
generic_update_time fs/inode.c:1981 [inline]
inode_update_time fs/inode.c:1994 [inline]
__file_update_time fs/inode.c:2180 [inline]
file_update_time+0x187/0x1a0 fs/inode.c:2210
ext4_page_mkwrite+0x1f9/0x11a0 fs/ext4/inode.c:6284
do_page_mkwrite+0x153/0x3f0 mm/memory.c:2951
do_shared_fault mm/memory.c:4717 [inline]
do_fault mm/memory.c:4779 [inline]
do_pte_missing mm/memory.c:3689 [inline]
handle_pte_fault mm/memory.c:5047 [inline]
__handle_mm_fault mm/memory.c:5188 [inline]
handle_mm_fault+0x1a2c/0x4a50 mm/memory.c:5353
do_user_addr_fault+0x736/0x12d0 arch/x86/mm/fault.c:1371
handle_page_fault arch/x86/mm/fault.c:1463 [inline]
exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7fd4b0272f32
RSP: 002b:00007fff67f0fb50 EFLAGS: 00010202
RAX: 0000000000001008 RBX: 00007fd4b1155720 RCX: 0000000000000000
RDX: 0000001b2df23000 RSI: 0000000000000008 RDI: 00007fd4b1155720
RBP: 0000000000000381 R08: 00007fd4b0610000 R09: 00007fd4b0626038
R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff8a7fe7da
R13: 00007fd4b0626038 R14: 000000000000000a R15: fffffffffffff000
</TASK>
INFO: task syz.2.93:6054 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.93 state:D stack:27048 pid:6054 ppid:5784 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
io_schedule+0x80/0xd0 kernel/sched/core.c:9024
bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:209
__wait_on_bit+0x9f/0x2c0 kernel/sched/wait_bit.c:49
out_of_line_wait_on_bit+0x13c/0x190 kernel/sched/wait_bit.c:64
wait_on_bit_io include/linux/wait_bit.h:101 [inline]
do_get_write_access+0x5c9/0xe00 fs/jbd2/transaction.c:1096
jbd2_journal_get_write_access+0x10c/0x140 fs/jbd2/transaction.c:1231
__ext4_journal_get_write_access+0x208/0x6d0 fs/ext4/ext4_jbd2.c:241
ext4_reserve_inode_write+0x205/0x2a0 fs/ext4/inode.c:5945
__ext4_mark_inode_dirty+0x13f/0x720 fs/ext4/inode.c:6129
ext4_dirty_inode+0xcb/0x110 fs/ext4/inode.c:6166
__mark_inode_dirty+0x2cc/0xc90 fs/fs-writeback.c:2537
generic_update_time fs/inode.c:1981 [inline]
inode_update_time fs/inode.c:1994 [inline]
__file_update_time fs/inode.c:2180 [inline]
file_update_time+0x187/0x1a0 fs/inode.c:2210
ext4_page_mkwrite+0x1f9/0x11a0 fs/ext4/inode.c:6284
do_page_mkwrite+0x153/0x3f0 mm/memory.c:2951
do_shared_fault mm/memory.c:4717 [inline]
do_fault mm/memory.c:4779 [inline]
do_pte_missing mm/memory.c:3689 [inline]
handle_pte_fault mm/memory.c:5047 [inline]
__handle_mm_fault mm/memory.c:5188 [inline]
handle_mm_fault+0x1a2c/0x4a50 mm/memory.c:5353
do_user_addr_fault+0x736/0x12d0 arch/x86/mm/fault.c:1371
handle_page_fault arch/x86/mm/fault.c:1463 [inline]
exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f4fcc072f32
RSP: 002b:00007ffe1bc28520 EFLAGS: 00010202
RAX: 0000000000006008 RBX: 00007f4fccf55720 RCX: 0000000000000000
RDX: 0000001b2e01e000 RSI: 0000000000000008 RDI: 00007f4fccf55720
RBP: 000000000000065f R08: 00007f4fcc410000 R09: 00007f4fcc426038
R10: 0000000000000003 R11: 0000000000000002 R12: ffffffff8308673c
R13: 00007f4fcc426038 R14: 00000000000001f9 R15: ffffffffffffa000
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6669
3 locks held by kworker/u4:12/3547:
#0: ffff888142a65138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#0: ffff888142a65138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#1: ffffc9000ce37d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#1: ffffc9000ce37d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#2: ffff88807e536c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1768 [inline]
#2: ffff88807e536c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1a4/0x350 fs/ext4/inode.c:2821
2 locks held by getty/5532:
#0: ffff88814cde20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
3 locks held by syz-executor/5764:
#0: ffff88802e62f3a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
#0: ffff88802e62f3a0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
#0: ffff88802e62f3a0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
#1: ffff88807e534510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
#1: ffff88807e534510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
#1: ffff88807e534510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
#2: ffff88807e538990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
2 locks held by syz.0.71/6010:
#0: ffff88807e5340e0 (&type->s_umount_key#31){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807e5340e0 (&type->s_umount_key#31){++++}-{3:3}, at: super_lock+0x189/0x390 fs/super.c:117
#1: ffff888024346820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff888024346820 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2842
3 locks held by syz.3.91/6046:
#0: ffff88807b6a9e20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
#0: ffff88807b6a9e20 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
#0: ffff88807b6a9e20 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
#1: ffff88807e534510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
#1: ffff88807e534510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
#1: ffff88807e534510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
#2: ffff88807e538990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
3 locks held by syz.1.92/6049:
#0: ffff88807b6a8b20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
#0: ffff88807b6a8b20 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
#0: ffff88807b6a8b20 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
#1: ffff88807e534510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
#1: ffff88807e534510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
#1: ffff88807e534510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
#2: ffff88807e538990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
3 locks held by syz.2.93/6054:
#0: ffff88807b6a81a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
#0: ffff88807b6a81a0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
#0: ffff88807b6a81a0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
#1: ffff88807e534510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
#1: ffff88807e534510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
#1: ffff88807e534510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
#2: ffff88807e538990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
<TASK>
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf59/0xfa0 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5819 Comm: kworker/0:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: events_power_efficient wg_ratelimiter_gc_entries
RIP: 0010:debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
RIP: 0010:do_raw_spin_lock+0x9f/0x2b0 kernel/locking/spinlock_debug.c:114
Code: 0f b6 04 28 84 c0 0f 85 c3 01 00 00 41 8b 06 3d ad 4e ad de 0f 85 14 01 00 00 4c 8d 7b 10 4d 89 fe 49 c1 ee 03 43 80 3c 2e 00 <74> 08 4c 89 ff e8 27 4b 76 00 4c 89 7c 24 18 49 8b 07 65 48 8b 0d
RSP: 0018:ffffc9000482faa0 EFLAGS: 00000246
RAX: 00000000dead4ead RBX: ffffffff8db86aa0 RCX: 653af8b54a7cc800
RDX: 0000000000000000 RSI: ffffffff8acade60 RDI: ffffffff8db86aa0
RBP: ffffc9000482fb58 R08: dffffc0000000000 R09: 1ffffffff223e0bc
R10: dffffc0000000000 R11: fffffbfff223e0bd R12: 1ffff92000905f58
R13: dffffc0000000000 R14: 1ffffffff1b70d56 R15: ffffffff8db86ab0
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a208b9a270 CR3: 000000000cf32000 CR4: 00000000003506f0
Call Trace:
<TASK>
spin_lock include/linux/spinlock.h:351 [inline]
wg_ratelimiter_gc_entries+0x5d/0x450 drivers/net/wireguard/ratelimiter.c:63
process_one_work kernel/workqueue.c:2657 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
* Struck through repros no longer work on HEAD.