INFO: task syz.8.438:7048 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.438 state:D stack:28704 pid: 7048 ppid: 5793 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
rwsem_down_read_slowpath+0x528/0x990 kernel/locking/rwsem.c:1055
__down_read_common kernel/locking/rwsem.c:1239 [inline]
__down_read kernel/locking/rwsem.c:1252 [inline]
down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500
iterate_supers+0xa4/0x1d0 fs/super.c:716
ksys_sync+0x91/0x150 fs/sync.c:102
__ia32_sys_sync+0xa/0x10 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f745259e749
RSP: 002b:00007f7450805038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f74527f4fa0 RCX: 00007f745259e749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f74527f4fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f74527f5038 R14: 00007f74527f4fa0 R15: 00007ffe8c671a68
INFO: task syz.8.438:7052 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.438 state:D stack:28776 pid: 7052 ppid: 5793 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
rwsem_down_read_slowpath+0x528/0x990 kernel/locking/rwsem.c:1055
__down_read_common kernel/locking/rwsem.c:1239 [inline]
__down_read kernel/locking/rwsem.c:1252 [inline]
down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500
iterate_supers+0xa4/0x1d0 fs/super.c:716
ksys_sync+0x91/0x150 fs/sync.c:102
__ia32_sys_sync+0xa/0x10 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f745259e749
RSP: 002b:00007f74507e4038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f74527f5090 RCX: 00007f745259e749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f74527f5090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f74527f5128 R14: 00007f74527f5090 R15: 00007ffe8c671a68
INFO: task syz.8.438:7055 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.438 state:D stack:27040 pid: 7055 ppid: 5793 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
rwsem_down_read_slowpath+0x528/0x990 kernel/locking/rwsem.c:1055
__down_read_common kernel/locking/rwsem.c:1239 [inline]
__down_read kernel/locking/rwsem.c:1252 [inline]
down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500
iterate_supers+0xa4/0x1d0 fs/super.c:716
ksys_sync+0x91/0x150 fs/sync.c:102
__ia32_sys_sync+0xa/0x10 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f745259e749
RSP: 002b:00007f74507c3038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f74527f5180 RCX: 00007f745259e749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f74527f5180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f74527f5218 R14: 00007f74527f5180 R15: 00007ffe8c671a68
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by udevd/3560:
2 locks held by getty/3944:
#0: ffff88814cc2c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900025ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
6 locks held by kworker/0:4/4228:
#0: ffff8880193fdd38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc900031ffd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffff888023b62220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
#2: ffff888023b62220 (&dev->mutex){....}-{3:3}, at: hub_event+0x1a7/0x5560 drivers/usb/core/hub.c:5827
#3: ffff888023b655c0 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3168 [inline]
#3: ffff888023b655c0 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5393 [inline]
#3: ffff888023b655c0 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
#3: ffff888023b655c0 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5799 [inline]
#3: ffff888023b655c0 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x2234/0x5560 drivers/usb/core/hub.c:5881
#4: ffff888023692468 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5394 [inline]
#4: ffff888023692468 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
#4: ffff888023692468 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5799 [inline]
#4: ffff888023692468 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x226d/0x5560 drivers/usb/core/hub.c:5881
#5: ffffffff8cb983b0 (ehci_cf_port_reset_rwsem){.+.+}-{3:3}, at: hub_port_reset+0x14f/0x18d0 drivers/usb/core/hub.c:3030
3 locks held by kworker/0:14/4440:
#0: ffff8880193fdd38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc900036dfd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffff88814860a220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
#2: ffff88814860a220 (&dev->mutex){....}-{3:3}, at: hub_event+0x1a7/0x5560 drivers/usb/core/hub.c:5827
3 locks held by kworker/u4:10/4622:
1 lock held by syz-executor/4756:
#0: ffff888061a240e0 (&type->s_umount_key#55){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz.8.438/7048:
#0: ffff888061a240e0 (&type->s_umount_key#55){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
1 lock held by syz.8.438/7052:
#0: ffff888061a240e0 (&type->s_umount_key#55){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
1 lock held by syz.8.438/7055:
#0: ffff888061a240e0 (&type->s_umount_key#55){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
1 lock held by syz.6.566/7796:
#0: ffff888061a240e0 (&type->s_umount_key#55){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
3 locks held by kworker/1:39/10194:
#0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000316fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffff888076a7a240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x271/0x3240 drivers/net/netdevsim/fib.c:1480
2 locks held by syz.0.948/10636:
1 lock held by syz.1.955/10720:
#0: ffffffff8c1210b0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4b0 kernel/rcu/tree.c:4043
1 lock held by syz.8.960/10722:
#0: ffff888078774460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386
3 locks held by syz.8.960/10723:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 10636 Comm: syz.0.948 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:shmem_acct_block mm/shmem.c:202 [inline]
RIP: 0010:shmem_inode_acct_block mm/shmem.c:217 [inline]
RIP: 0010:shmem_alloc_and_acct_page+0x155/0xb70 mm/shmem.c:1605
Code: 38 4c 89 fe 48 81 e6 00 00 20 00 31 ff e8 c3 9b d2 ff 49 81 e7 00 00 20 00 75 07 e8 d5 97 d2 ff eb 6a 65 4c 8b 3d 7b 3b 5d 7e <49> 81 c7 10 05 00 00 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc
RSP: 0018:ffffc90003c7f620 EFLAGS: 00000206
RAX: ffffffff81a5342d RBX: 0000000000000000 RCX: ffff88801ea23b80
RDX: 0000000000000002 RSI: 0000000000200000 RDI: 0000000000000000
RBP: ffffc90003c7f920 R08: ffff88801ea23b80 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000002 R12: 0000000000000001
R13: ffff888058efeae0 R14: ffff888016873400 R15: ffff88801ea23b80
FS: 00007f68c754c6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c360f54 CR3: 0000000048408000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
shmem_getpage_gfp+0x14f4/0x2d40 mm/shmem.c:1906
shmem_getpage mm/shmem.c:151 [inline]
shmem_write_begin+0xcd/0x1a0 mm/shmem.c:2474
generic_perform_write+0x2aa/0x530 mm/filemap.c:3785
__generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912
generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944
call_write_iter include/linux/fs.h:2173 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x712/0xd00 fs/read_write.c:594
ksys_write+0x14d/0x250 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f68c92e41ff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007f68c754bdf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f68c92e41ff
RDX: 0000000001000000 RSI: 00007f68bf10b000 RDI: 0000000000000006
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000009641
R10: 0000200000012cc2 R11: 0000000000000293 R12: 0000000000000006
R13: 00007f68c754bef0 R14: 00007f68c754beb0 R15: 00007f68bf10b000