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: 52d, last: 4d18h
Sample crash report:
INFO: task kworker/u4:11:3527 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:11 state:D stack:20568 pid:3527 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:1686
writeback_sb_inodes+0x813/0x1020 fs/fs-writeback.c:1977
__writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2048
wb_writeback+0x472/0xbe0 fs/fs-writeback.c:2158
wb_check_background_flush fs/fs-writeback.c:2228 [inline]
wb_do_writeback fs/fs-writeback.c:2316 [inline]
wb_workfn+0xb8e/0xe60 fs/fs-writeback.c:2343
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 jbd2/sda1-8:5104 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:jbd2/sda1-8 state:D stack:25736 pid:5104 ppid:2 flags:0x00004000
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_buffer include/linux/buffer_head.h:373 [inline]
jbd2_journal_commit_transaction+0x2e8d/0x5ad0 fs/jbd2/commit.c:815
kjournald2+0x40f/0x810 fs/jbd2/journal.c:201
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:5766 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22408 pid:5766 ppid:5765 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:2522
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: 0033:0x7f6e78e7c6e2
RSP: 002b:00007ffc3e7d4640 EFLAGS: 00010202
RAX: 00007f6e76c7c000 RBX: 000055556452be20 RCX: 0000000000000001
RDX: 0000000000000c56 RSI: 00005555645278b8 RDI: 0000000000000002
RBP: 00007ffc3e7d4b40 R08: 00005555645278c0 R09: 0000000000000091
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffc3e7d4980
R13: 00007ffc3e7d4770 R14: 585858582e7a7973 R15: 00007ffc3e7d46c0
</TASK>
INFO: task syz.0.48:5953 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.48 state:D stack:27560 pid:5953 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
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:2522
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: 0033:0x7f36bcc6baa3
RSP: 002b:00007ffde542dde0 EFLAGS: 00010246
RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000001b2d964000
RDX: 0000001b2d924000 RSI: 0000000000600000 RDI: 00007f36bcfe0708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffde542e070
</TASK>
INFO: task syz.3.49:5954 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.49 state:D stack:27560 pid:5954 ppid:5780 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:2522
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: 0033:0x7efef7e6baa3
RSP: 002b:00007ffeed9dd3c0 EFLAGS: 00010246
RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000001b2dc64000
RDX: 0000001b2dc24000 RSI: 0000000000600000 RDI: 00007efef81e0708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffeed9dd650
</TASK>
INFO: task syz.2.51:5955 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.51 state:D stack:27560 pid:5955 ppid:5779 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:2522
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: 0033:0x7fbea5a6baa3
RSP: 002b:00007ffdf8f0afe0 EFLAGS: 00010246
RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000001b2db64000
RDX: 0000001b2db24000 RSI: 0000000000600000 RDI: 00007fbea5de0708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffdf8f0b270
</TASK>
INFO: task syz.1.50:5956 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.50 state:D stack:27560 pid:5956 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:2522
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: 0033:0x7f93b346baa3
RSP: 002b:00007ffc35cd35a0 EFLAGS: 00010246
RAX: 00000000005ffde8 RBX: 0000000000000000 RCX: 0000001b2da64000
RDX: 0000001b2da24000 RSI: 0000000000600000 RDI: 00007f93b37e0708
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffc35cd3830
</TASK>
Showing all locks held in the system:
5 locks held by kworker/u4:0/11:
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:6635
3 locks held by kworker/u4:9/2978:
#0: ffff8880b8f3c258 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559
#1: ffff8880b8f28a00 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
#1: ffff8880b8f28a00 (psi_seq){-.-.}-{0:0}, at: __schedule+0x21d3/0x4660 kernel/sched/core.c:6696
#2: ffff8880b8f3c258 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559
4 locks held by kworker/u4:11/3527:
#0: ffff88801ce5fd38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#0: ffff88801ce5fd38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#1: ffffc9000cbb7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#1: ffffc9000cbb7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#2: ffff888031e740e0 (&type->s_umount_key#31){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
#3: ffff888031e76c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1768 [inline]
#3: ffff888031e76c58 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1a4/0x350 fs/ext4/inode.c:2821
2 locks held by getty/5535:
#0: ffff88802d70d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
3 locks held by syz-executor/5766:
#0: ffff88802fb114a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
#0: ffff88802fb114a0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
#0: ffff88802fb114a0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
#2: ffff888031e80990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
3 locks held by syz.0.48/5953:
#0: ffff88802a763120 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
#0: ffff88802a763120 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
#0: ffff88802a763120 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
#2: ffff888031e80990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
3 locks held by syz.3.49/5954:
#0: ffff88802cabbaa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
#0: ffff88802cabbaa0 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
#0: ffff88802cabbaa0 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
#2: ffff888031e80990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
3 locks held by syz.2.51/5955:
#0: ffff88802cabb120 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
#0: ffff88802cabb120 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
#0: ffff88802cabb120 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
#2: ffff888031e80990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
3 locks held by syz.1.50/5956:
#0: ffff88802a764420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
#0: ffff88802a764420 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5380 [inline]
#0: ffff88802a764420 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x32/0x2f0 mm/memory.c:5440
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1633 [inline]
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1737 [inline]
#1: ffff888031e74510 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1e2/0x11a0 fs/ext4/inode.c:6283
#2: ffff888031e80990 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1f3f/0x2170 fs/jbd2/transaction.c:448
=============================================
NMI backtrace for cpu 0
CPU: 0 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148
Code: 89 18 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 03 f6 36 00 fb f4 <c3> 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2c 89 cb 80 f9
RSP: 0018:ffffc90000187de0 EFLAGS: 000002c6
RAX: a7a5a8451f6c0e00 RBX: ffffffff81631e24 RCX: a7a5a8451f6c0e00
RDX: 0000000000000001 RSI: ffffffff8acacce0 RDI: ffffffff8b1d3ba0
RBP: ffffc90000187f20 R08: ffff8880b8f36b6b R09: 1ffff110171e6d6d
R10: dffffc0000000000 R11: ffffed10171e6d6e R12: 1ffff92000030fc8
R13: dffffc0000000000 R14: 1ffff11003848780 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005613b4c51a38 CR3: 000000007dfcf000 CR4: 00000000003506e0
Call Trace:
<TASK>
arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:753
default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
cpuidle_idle_call kernel/sched/idle.c:178 [inline]
do_idle+0x334/0x5c0 kernel/sched/idle.c:302
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401
start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323
secondary_startup_64_no_verify+0x179/0x17b
</TASK>
* Struck through repros no longer work on HEAD.