INFO: task syz.5.2406:15084 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.5.2406 state:D stack:28160 pid:15084 tgid:15078 ppid:10685 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5310 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
bdev_open+0xe0/0xd30 block/bdev.c:961
blkdev_open+0x470/0x610 block/fops.c:698
do_dentry_open+0x785/0x14e0 fs/open.c:949
vfs_open+0x3b/0x340 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x2e08/0x3860 fs/namei.c:4830
do_file_open+0x23e/0x4a0 fs/namei.c:4859
do_sys_openat2+0x113/0x200 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1383
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: 0033:0x7f9948d5b78e
RSP: 002b:00007f9949cf2b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f9949cf36c0 RCX: 00007f9948d5b78e
RDX: 0000000000000002 RSI: 00007f9949cf2c00 RDI: ffffffffffffff9c
RBP: 00007f9949cf2c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f9949016128 R14: 00007f9949016090 R15: 00007ffc41aec9b8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e960320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e960320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e960320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5580:
#0: ffff888033b0e0a0 (&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
1 lock held by udevd/6302:
#0: ffff888027474358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
1 lock held by syz.5.2406/15084:
#0: ffff888027474358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
1 lock held by syz.6.3386/19723:
#0: ffff88805ee50208 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#0: ffff88805ee50208 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __sock_release+0x89/0x250 net/socket.c:665
=============================================
NMI backtrace for cpu 0
CPU: 0 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 01/24/2026
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:347 [inline]
watchdog+0x103d/0x1090 kernel/hung_task.c:516
kthread+0x388/0x470 kernel/kthread.c:467
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:37 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:139 [inline]
RIP: 0010:wrmsrq arch/x86/include/asm/msr.h:199 [inline]
RIP: 0010:native_apic_msr_write+0x39/0x50 arch/x86/include/asm/apic.h:208
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 cc cc cc cc cc 89 f6 31 d2 e9 66 07 7f 03 66 0f 1f 44 00
RSP: 0018:ffffc90000a08e48 EFLAGS: 00000046
RAX: 0000000000040b3d RBX: ffff8880b8523e40 RCX: 0000000000000838
RDX: 0000000000000000 RSI: 0000000000040b3d RDI: 0000000000000838
RBP: 0000000000000000 R08: ffffffff81b31d85 R09: ffffffff9a505508
R10: 0000000000000003 R11: ffffffff81742750 R12: 0000000010005235
R13: dffffc0000000000 R14: 0000000000040b3d R15: 0000000000000020
FS: 0000000000000000(0000) GS:ffff888125115000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f70089e4198 CR3: 0000000044e50000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
apic_write arch/x86/include/asm/apic.h:405 [inline]
lapic_next_event+0x11/0x20 arch/x86/kernel/apic/apic.c:418
clockevents_program_event+0x1c9/0x350 kernel/time/clockevents.c:334
hrtimer_interrupt+0xb08/0x1010 kernel/time/hrtimer.c:1924
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x460 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 6e 73 02 c3 cc cc cc cc cc cc cc 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 ad 10 00 fb f4 7c ea 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 00000246
RAX: 000000000088134b RBX: ffffffff819ae1ed RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8e006fa9 RDI: ffffffff8c298600
RBP: ffffc90000197f10 R08: ffff8880b853395b R09: 1ffff110170a672b
R10: dffffc0000000000 R11: ffffed10170a672c R12: ffffffff903342b0
R13: 1ffff11003bd3000 R14: 0000000000000001 R15: 0000000000000001
arch_safe_halt arch/x86/kernel/process.c:766 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1bd/0x500 kernel/sched/idle.c:332
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147
----------------
Code disassembly (best guess):
0: 74 2a je 0x2c
2: 83 ff 30 cmp $0x30,%edi
5: 74 25 je 0x2c
7: eb 10 jmp 0x19
9: 81 ff d0 00 00 00 cmp $0xd0,%edi
f: 74 1b je 0x2c
11: 81 ff e0 00 00 00 cmp $0xe0,%edi
17: 74 13 je 0x2c
19: c1 ef 04 shr $0x4,%edi
1c: 81 c7 00 08 00 00 add $0x800,%edi
22: 89 f9 mov %edi,%ecx
24: 89 f0 mov %esi,%eax
26: 31 d2 xor %edx,%edx
28: 0f 30 wrmsr
* 2a: 66 90 xchg %ax,%ax <-- trapping instruction
2c: c3 ret
2d: cc int3
2e: cc int3
2f: cc int3
30: cc int3
31: cc int3
32: 89 f6 mov %esi,%esi
34: 31 d2 xor %edx,%edx
36: e9 66 07 7f 03 jmp 0x37f07a1
3b: 66 data16
3c: 0f .byte 0xf
3d: 1f (bad)
3e: 44 rex.R