INFO: task syz.1.1935:13933 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1935 state:D stack:25536 pid:13933 tgid:13924 ppid:5815 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
wait_for_reconnect drivers/block/nbd.c:1110 [inline]
nbd_handle_cmd drivers/block/nbd.c:1152 [inline]
nbd_queue_rq+0xd12/0x12d0 drivers/block/nbd.c:1210
blk_mq_dispatch_rq_list+0x416/0x1e20 block/blk-mq.c:2129
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xcb7/0x15f0 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd8/0x1b0 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x239/0x670 block/blk-mq.c:2367
blk_mq_dispatch_list+0x514/0x1310 block/blk-mq.c:2928
blk_mq_flush_plug_list block/blk-mq.c:2976 [inline]
blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2948
__blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1225
blk_finish_plug block/blk-core.c:1252 [inline]
blk_finish_plug block/blk-core.c:1249 [inline]
__submit_bio+0x545/0x690 block/blk-core.c:651
__submit_bio_noacct_mq block/blk-core.c:724 [inline]
submit_bio_noacct_nocheck+0x53d/0xc10 block/blk-core.c:755
submit_bio_noacct+0xbbb/0x1f60 block/blk-core.c:879
submit_bio_wait+0x110/0x250 block/bio.c:1388
bdev_rw_virt+0x157/0x1f0 block/bio.c:1419
hib_submit_io_sync kernel/power/swap.c:273 [inline]
swsusp_check+0x103/0x440 kernel/power/swap.c:1581
software_resume+0x6f/0x4e0 kernel/power/hibernate.c:1053
resume_store+0x247/0x460 kernel/power/hibernate.c:1338
kobj_attr_store+0x58/0x80 lib/kobject.c:840
sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142
kernfs_fop_write_iter+0x3af/0x570 fs/kernfs/file.c:352
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x7d3/0x11d0 fs/read_write.c:686
ksys_write+0x12a/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5caa58efc9
RSP: 002b:00007f5cab364038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5caa7e6180 RCX: 00007f5caa58efc9
RDX: 0000000000000012 RSI: 0000200000000000 RDI: 000000000000000b
RBP: 00007f5caa611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5caa7e6218 R14: 00007f5caa7e6180 R15: 00007ffdd46bd9e8
INFO: task syz.0.1987:14155 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1987 state:D stack:26936 pid:14155 tgid:14152 ppid:5808 task_flags:0x408140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
lock_system_sleep+0x87/0xa0 kernel/power/main.c:57
snapshot_open+0x3f/0x2b0 kernel/power/user.c:56
misc_open+0x26d/0x450 drivers/char/misc.c:163
chrdev_open+0x234/0x6a0 fs/char_dev.c:414
do_dentry_open+0x982/0x1530 fs/open.c:965
vfs_open+0x82/0x3f0 fs/open.c:1097
do_open fs/namei.c:3975 [inline]
path_openat+0x1de4/0x2cb0 fs/namei.c:4134
do_filp_open+0x20b/0x470 fs/namei.c:4161
do_sys_openat2+0x11b/0x1d0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f05d2d8efc9
RSP: 002b:00007f05d3bbe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f05d2fe6180 RCX: 00007f05d2d8efc9
RDX: 0000000000040000 RSI: 0000200000000680 RDI: ffffffffffffff9c
RBP: 00007f05d2e11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000019 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f05d2fe6218 R14: 00007f05d2fe6180 R15: 00007fff2f55ce58
INFO: task syz.7.1990:14164 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.1990 state:D stack:26440 pid:14164 tgid:14163 ppid:11883 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
misc_open+0x63/0x450 drivers/char/misc.c:125
chrdev_open+0x234/0x6a0 fs/char_dev.c:414
do_dentry_open+0x982/0x1530 fs/open.c:965
vfs_open+0x82/0x3f0 fs/open.c:1097
do_open fs/namei.c:3975 [inline]
path_openat+0x1de4/0x2cb0 fs/namei.c:4134
do_filp_open+0x20b/0x470 fs/namei.c:4161
do_sys_openat2+0x11b/0x1d0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2dbb38d810
RSP: 002b:00007f2dbc240ef0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f2dbb38d810
RDX: 0000000000000002 RSI: 00007f2dbb411c6c RDI: 00000000ffffff9c
RBP: 00007f2dbb411c6c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000024 R14: 0000200000000500 R15: 00007ffc9245d4e8
INFO: task syz.6.1991:14166 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.1991 state:D stack:26472 pid:14166 tgid:14165 ppid:7596 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
misc_open+0x63/0x450 drivers/char/misc.c:125
chrdev_open+0x234/0x6a0 fs/char_dev.c:414
do_dentry_open+0x982/0x1530 fs/open.c:965
vfs_open+0x82/0x3f0 fs/open.c:1097
do_open fs/namei.c:3975 [inline]
path_openat+0x1de4/0x2cb0 fs/namei.c:4134
do_filp_open+0x20b/0x470 fs/namei.c:4161
do_sys_openat2+0x11b/0x1d0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faf1738efc9
RSP: 002b:00007faf18236038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007faf175e5fa0 RCX: 00007faf1738efc9
RDX: 0000000000000000 RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007faf17411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007faf175e6038 R14: 00007faf175e5fa0 R15: 00007ffd05688df8
INFO: task syz.3.1993:14174 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1993 state:D stack:28856 pid:14174 tgid:14173 ppid:5823 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760
misc_open+0x63/0x450 drivers/char/misc.c:125
chrdev_open+0x234/0x6a0 fs/char_dev.c:414
do_dentry_open+0x982/0x1530 fs/open.c:965
vfs_open+0x82/0x3f0 fs/open.c:1097
do_open fs/namei.c:3975 [inline]
path_openat+0x1de4/0x2cb0 fs/namei.c:4134
do_filp_open+0x20b/0x470 fs/namei.c:4161
do_sys_openat2+0x11b/0x1d0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f680dd8d810
RSP: 002b:00007f680bff3ef0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f680dd8d810
RDX: 0000000000000002 RSI: 00007f680de11c6c RDI: 00000000ffffff9c
RBP: 00007f680de11c6c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000036 R14: 00002000000000c0 R15: 00007ffdeefc7c08
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e3c4460 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3c4460 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e3c4460 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
2 locks held by getty/5576:
#0: ffff88814d32a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
7 locks held by syz.1.1935/13933:
#0: ffff8880321b2ef8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1232
#1: ffff888030e9e420 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738
#2: ffff888058514c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x570 fs/kernfs/file.c:343
#3: ffff88801dacf878 (kn->active#66){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#3: ffff88801dacf878 (kn->active#66){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2ff/0x570 fs/kernfs/file.c:344
#4: ffffffff8e287968 (system_transition_mutex){+.+.}-{4:4}, at: software_resume+0x65/0x4e0 kernel/power/hibernate.c:1052
#5: ffff888025cd7f10 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#5: ffff888025cd7f10 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#5: ffff888025cd7f10 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x22b/0x670 block/blk-mq.c:2367
#6: ffff88802681b238 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xbd/0x12d0 drivers/block/nbd.c:1202
2 locks held by syz.0.1987/14155:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
#1: ffffffff8e287968 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x87/0xa0 kernel/power/main.c:57
1 lock held by syz.7.1990/14164:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz.6.1991/14166:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz.3.1993/14174:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14176:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14178:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14181:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14182:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14184:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14190:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14194:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14195:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14196:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14198:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14204:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14208:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14209:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14210:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
1 lock held by syz-executor/14212:
#0: ffffffff8f074028 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x450 drivers/char/misc.c:125
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf3f/0x1170 kernel/hung_task.c:495
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 07 6d 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 d5 29 00 fb f4 3c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6
RAX: 0000000001a4dbb5 RBX: 0000000000000001 RCX: ffffffff8b6052a9
RDX: 0000000000000000 RSI: ffffffff8da2a259 RDI: ffffffff8bf06e40
RBP: ffffed1003ad7490 R08: 0000000000000001 R09: ffffed10170a6655
R10: ffff8880b85332ab R11: 0000000000000001 R12: 0000000000000001
R13: ffff88801d6ba480 R14: ffffffff9081f6d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124b0a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562c2c363ad0 CR3: 000000000e182000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x38d/0x500 kernel/sched/idle.c:330
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x148