INFO: task syz-executor:5598 blocked in I/O wait 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:21736 pid:5598 tgid:5598 ppid:5597 task_flags:0x440100 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7270
schedule
__schedule_loop kernel/sched/core.c:7347 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7362
io_schedule+0x7f/0xd0 kernel/sched/core.c:8190
bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258
__wait_on_bit+0xac/0x300 kernel/sched/wait_bit.c:52
out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67
wait_on_bit_io include/linux/wait_bit.h:106 [inline]
do_get_write_access+0x662/0x1070 fs/jbd2/transaction.c:1113
jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263
__ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249
ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6509
__ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6694
ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6731
__mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729
generic_update_time fs/inode.c:2253 [inline]
file_update_time_flags+0x399/0x440 fs/inode.c:2483
ext4_page_mkwrite+0x224/0x1140 fs/ext4/inode.c:6897
do_page_mkwrite+0x147/0x310 mm/memory.c:3816
wp_page_shared mm/memory.c:4217 [inline]
do_wp_page+0x1a9c/0x4b80 mm/memory.c:4440
handle_pte_fault mm/memory.c:6582 [inline]
__handle_mm_fault mm/memory.c:6707 [inline]
handle_mm_fault+0x15d7/0x3750 mm/memory.c:6876
do_user_addr_fault+0xa4f/0x1340 arch/x86/mm/fault.c:1343
handle_page_fault arch/x86/mm/fault.c:1483 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f384aa702ea
RSP: 002b:00007ffcc4345450 EFLAGS: 00010202
RAX: 00007f38421ffba8 RBX: 00007ffcc4345580 RCX: 0000000000000000
RDX: 00007f3841e00218 RSI: 0000000000000002 RDI: 00007ffcc4345580
RBP: 00000000000003e6 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffcc4345560 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000456 R14: 0000000000000002 R15: 0000000000000002
INFO: task syz.6.1895:13264 blocked in I/O wait for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.1895 state:D stack:25352 pid:13264 tgid:13264 ppid:6576 task_flags:0x440040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7270
__schedule_loop kernel/sched/core.c:7347 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7362
io_schedule+0x7f/0xd0 kernel/sched/core.c:8190
bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258
__wait_on_bit+0xac/0x300 kernel/sched/wait_bit.c:52
out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67
wait_on_bit_io include/linux/wait_bit.h:106 [inline]
do_get_write_access+0x662/0x1070 fs/jbd2/transaction.c:1113
jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263
__ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249
ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6509
__ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6694
ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6731
__mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729
generic_update_time fs/inode.c:2253 [inline]
file_update_time_flags+0x399/0x440 fs/inode.c:2483
ext4_page_mkwrite+0x224/0x1140 fs/ext4/inode.c:6897
do_page_mkwrite+0x147/0x310 mm/memory.c:3816
do_shared_fault mm/memory.c:6076 [inline]
do_fault mm/memory.c:6138 [inline]
do_pte_missing+0x757/0x34b0 mm/memory.c:4700
handle_pte_fault mm/memory.c:6558 [inline]
__handle_mm_fault mm/memory.c:6707 [inline]
handle_mm_fault+0x1a53/0x3750 mm/memory.c:6876
do_user_addr_fault+0xa4f/0x1340 arch/x86/mm/fault.c:1343
handle_page_fault arch/x86/mm/fault.c:1483 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7fa4cb0727a9
RSP: 002b:00007ffd2f3063a0 EFLAGS: 00010202
RAX: 0000001b2f423000 RBX: ffffffff8be22285 RCX: 0000001b2f422ff8
RDX: 0000001b2f024224 RSI: 0000000000000008 RDI: 00007fa4cbf55720
RBP: 00000000000001d4 R08: 00007fa4cb410000 R09: 00007fa4cb412000
R10: 000000008be22289 R11: 000000000000000e R12: 00007fa4cb426128
R13: 0000000000000574 R14: ffffffff8be221d9 R15: 00007fa4cbf55720
INFO: task syz.9.1893:13273 blocked in I/O wait for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.1893 state:D stack:27248 pid:13273 tgid:13273 ppid:10945 task_flags:0x440040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7270
__schedule_loop kernel/sched/core.c:7347 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7362
io_schedule+0x7f/0xd0 kernel/sched/core.c:8190
bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:258
__wait_on_bit+0xac/0x300 kernel/sched/wait_bit.c:52
out_of_line_wait_on_bit+0x13b/0x190 kernel/sched/wait_bit.c:67
wait_on_bit_io include/linux/wait_bit.h:106 [inline]
do_get_write_access+0x662/0x1070 fs/jbd2/transaction.c:1113
jbd2_journal_get_write_access+0x1d7/0x230 fs/jbd2/transaction.c:1263
__ext4_journal_get_write_access+0xf1/0x620 fs/ext4/ext4_jbd2.c:249
ext4_reserve_inode_write+0x294/0x360 fs/ext4/inode.c:6509
__ext4_mark_inode_dirty+0x146/0x7b0 fs/ext4/inode.c:6694
ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6731
__mark_inode_dirty+0x3a8/0x13b0 fs/fs-writeback.c:2729
generic_update_time fs/inode.c:2253 [inline]
touch_atime+0x568/0x670 fs/inode.c:2328
file_accessed include/linux/fs.h:2277 [inline]
ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:901
vfs_mmap_prepare include/linux/fs.h:2069 [inline]
call_mmap_prepare mm/vma.c:2776 [inline]
__mmap_region mm/vma.c:2863 [inline]
mmap_region+0xe8a/0x2240 mm/vma.c:2964
do_mmap+0xe0a/0x1300 mm/mmap.c:573
vm_mmap_pgoff+0x272/0x4e0 mm/util.c:581
ksys_mmap_pgoff+0x4dc/0x760 mm/mmap.c:619
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a1959dec2
RSP: 002b:00007fff49fce018 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000001b30064000 RCX: 00007f5a1959dec2
RDX: 0000000000000003 RSI: 00000000003c0000 RDI: 0000001b30064000
RBP: 0000000000100001 R08: 0000000000000004 R09: 0000000000040000
R10: 0000000000100001 R11: 0000000000000206 R12: 0000000000000048
R13: 00000000000927c0 R14: 00000000000ea34f R15: 00007fff49fce2f0
Showing all locks held in the system:
locks held by pr/ttyS0/16: 2, last CPU#0:
#0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
#0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
#1: ffffffff9ad33098 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
#1: ffffffff9ad33098 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x67/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by khungtaskd/32: 1, last CPU#1:
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6837
locks held by getty/5370: 2, on CPU#1:
#0: ffff8880357040a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/5598: 3, on CPU#0:
#0: ffff888074b4b1c8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310
#1: ffff8880293da558 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
#1: ffff8880293da558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline]
#1: ffff8880293da558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
#1: ffff8880293da558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x202/0x1140 fs/ext4/inode.c:6896
#2: ffff8880293ce938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444
locks held by syz.6.1895/13264: 3, on CPU#1:
#0: ffff88807ff7e088 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310
#1: ffff8880293da558 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
#1: ffff8880293da558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline]
#1: ffff8880293da558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline]
#1: ffff8880293da558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x202/0x1140 fs/ext4/inode.c:6896
#2: ffff8880293ce938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444
locks held by syz.9.1893/13273: 3, on CPU#1:
#0: ffff88807e25dcf8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#0: ffff88807e25dcf8 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0 mm/util.c:579
#1: ffff8880293da460 (sb_writers#4){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2277 [inline]
#1: ffff8880293da460 (sb_writers#4){.+.+}-{0:0}, at: ext4_file_mmap_prepare+0x277/0x450 fs/ext4/file.c:901
#2: ffff8880293ce938 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1fbf/0x2200 fs/jbd2/transaction.c:444
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409
Code: e8 fe 91 55 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 8f 69 c5 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 b5 17 9e fb cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900001578b8 EFLAGS: 00000002
RAX: 1ffffffff35a6600 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff857228d0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9ad330c0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124cd8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c1770c1660 CR3: 000000000eb48000 CR4: 0000000000350ef0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x184/0x2f0 drivers/tty/serial/8250/8250_port.c:2013
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3270 [inline]
__serial8250_console_fifo_write+0xcd/0x3e0 drivers/tty/serial/8250/8250_port.c:3345
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
__serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline]
serial8250_console_write+0xaa1/0x1200 drivers/tty/serial/8250/8250_port.c:3493
nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
nbcon_kthread_func+0x679/0x880 kernel/printk/nbcon.c:1271
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245