INFO: task syz.6.9088:9743 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.9088 state:D stack:28160 pid:9743 tgid:9742 ppid:2281 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7005
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7062
rwsem_down_read_slowpath+0x61e/0x920 kernel/locking/rwsem.c:1086
__down_read_common kernel/locking/rwsem.c:1261 [inline]
__down_read kernel/locking/rwsem.c:1274 [inline]
down_read+0x99/0x2e0 kernel/locking/rwsem.c:1539
inode_lock_shared include/linux/fs.h:1043 [inline]
blkdev_write_iter+0x50b/0x710 block/fops.c:800
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x61d/0xb90 fs/read_write.c:688
ksys_write+0x150/0x270 fs/read_write.c:740
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe999b9c799
RSP: 002b:00007fe99ab24028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fe999e15fa0 RCX: 00007fe999b9c799
RDX: 00000000fffffd2c RSI: 0000200000000000 RDI: 0000000000000007
RBP: 00007fe999c32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe999e16038 R14: 00007fe999e15fa0 R15: 00007fe999f3fa48
INFO: task syz.6.9088:9746 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.9088 state:D stack:28832 pid:9746 tgid:9742 ppid:2281 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7005
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7062
rwsem_down_read_slowpath+0x61e/0x920 kernel/locking/rwsem.c:1086
__down_read_common kernel/locking/rwsem.c:1261 [inline]
__down_read kernel/locking/rwsem.c:1274 [inline]
down_read+0x99/0x2e0 kernel/locking/rwsem.c:1539
inode_lock_shared include/linux/fs.h:1043 [inline]
blkdev_read_iter+0x2f8/0x440 block/fops.c:854
new_sync_read fs/read_write.c:493 [inline]
vfs_read+0x582/0xa70 fs/read_write.c:574
ksys_read+0x150/0x270 fs/read_write.c:717
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe999b9c799
RSP: 002b:00007fe99ab03028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fe999e16090 RCX: 00007fe999b9c799
RDX: 0000000000002020 RSI: 0000200000000640 RDI: 0000000000000007
RBP: 00007fe999c32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe999e16128 R14: 00007fe999e16090 R15: 00007fe999f3fa48
Showing all locks held in the system:
1 lock held by ksoftirqd/1/23:
1 lock held by khungtaskd/31:
#0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5579:
#0: ffff8880359230a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
2 locks held by syz.0.8742/8168:
#0: ffff88802359d828 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#0: ffff88802359d828 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: blkdev_fallocate+0x260/0x530 block/fops.c:907
#1: ffff88802359d9c8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock include/linux/fs.h:1083 [inline]
#1: ffff88802359d9c8 (mapping.invalidate_lock){++++}-{4:4}, at: blkdev_fallocate+0x290/0x530 block/fops.c:908
1 lock held by syz.6.9088/9743:
#0: ffff88802359d828 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline]
#0: ffff88802359d828 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: blkdev_write_iter+0x50b/0x710 block/fops.c:800
1 lock held by syz.6.9088/9746:
#0: ffff88802359d828 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline]
#0: ffff88802359d828 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: blkdev_read_iter+0x2f8/0x440 block/fops.c:854
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 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: 12524 Comm: kworker/0:9 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:__sanitizer_cov_trace_switch+0x81/0x130 kernel/kcov.c:350
Code: 00 00 00 b9 01 00 00 00 48 85 c0 0f 84 b3 00 00 00 41 57 41 56 41 54 53 48 8b 54 24 20 65 4c 8b 05 8c 5b 56 11 45 31 c9 eb 08 <49> ff c1 4c 39 c8 74 77 4e 8b 54 ce 10 65 44 8b 1d 9a 5b 56 11 41
RSP: 0018:ffffc9000fe2f0a8 EFLAGS: 00000293
RAX: 0000000000000008 RBX: dffffc0000000000 RCX: 0000000000000001
RDX: ffffffff8baa1458 RSI: ffffffff8ff89fc0 RDI: 0000000000000001
RBP: ffffffff8bcd89ab R08: ffff8880293f1e80 R09: 0000000000000002
R10: 0000000000000002 R11: 0000000000000000 R12: ffffc9000fe2f1c0
R13: ffffc9000fe2f3a7 R14: 0000000000000801 R15: ffffffff8bcd89a6
FS: 0000000000000000(0000) GS:ffff888125460000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056323223aa38 CR3: 000000000e54c000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
vsnprintf+0x118/0xee0 lib/vsprintf.c:2892
sprintf+0xe7/0x140 lib/vsprintf.c:3111
print_time kernel/printk/printk.c:1359 [inline]
info_print_prefix+0x16b/0x360 kernel/printk/printk.c:1385
record_print_text+0x176/0x450 kernel/printk/printk.c:1434
printk_get_next_message+0x29c/0x880 kernel/printk/printk.c:3072
console_emit_next_record kernel/printk/printk.c:3137 [inline]
console_flush_one_record kernel/printk/printk.c:3269 [inline]
console_flush_all+0x501/0xb20 kernel/printk/printk.c:3343
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
_printk+0xdd/0x130 kernel/printk/printk.c:2504
m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline]
m920x_rc_query+0x2f6/0x830 drivers/media/usb/dvb-usb/m920x.c:-1
legacy_dvb_usb_read_remote_control+0x107/0x450 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123
process_one_work kernel/workqueue.c:3275 [inline]
process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245