INFO: task syz.9.3124:18171 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.3124 state:D stack:23464 pid:18171 tgid:18171 ppid:14479 task_flags:0x400040 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
request_wait_answer fs/fuse/dev.c:585 [inline]
__fuse_request_send fs/fuse/dev.c:599 [inline]
__fuse_simple_request+0x11d2/0x1bb0 fs/fuse/dev.c:693
fuse_simple_request fs/fuse/fuse_i.h:1250 [inline]
fuse_flush+0x5dd/0x810 fs/fuse/file.c:482
filp_flush+0xc0/0x190 fs/open.c:1549
filp_close+0x1d/0x40 fs/open.c:1562
__range_close fs/file.c:767 [inline]
__do_sys_close_range fs/file.c:826 [inline]
__se_sys_close_range+0x35c/0x650 fs/file.c:790
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3bd9cff6c9
RSP: 002b:00007fffe0195758 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007f3bd9f57da0 RCX: 00007f3bd9cff6c9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f3bd9f57da0 R08: 00000000000000dc R09: 0000000ce0195a4f
R10: 00000000003ffd00 R11: 0000000000000246 R12: 00000000001cceeb
R13: 00007f3bd9f56090 R14: ffffffffffffffff R15: 00007fffe0195870
Showing all locks held in the system:
1 lock held by pr/legacy/17:
1 lock held by khungtaskd/38:
#0: ffffffff8d5aa800 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5aa800 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5aa800 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5560:
#0: ffff88823bf2c8a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222
2 locks held by kworker/0:5/5885:
6 locks held by kworker/u8:14/6320:
5 locks held by kworker/u8:28/6993:
3 locks held by kworker/1:0/11616:
6 locks held by kworker/0:2/12519:
4 locks held by kworker/u8:6/13523:
1 lock held by syz-executor/14548:
2 locks held by kworker/1:9/14779:
4 locks held by kworker/0:9/16163:
1 lock held by syz-executor/18472:
5 locks held by kworker/u8:13/19227:
1 lock held by syz-executor/19627:
1 lock held by syz.4.3583/19648:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/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+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 19627 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:check_preemption_disabled+0x40/0x120 lib/smp_processor_id.c:53
Code: 08 65 8b 05 d6 f4 e1 06 65 8b 0d cb f4 e1 06 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d ab f4 e1 06 48 3b 4c 24 08 0f 85 cc 00 00 00 <48> 83 c4 10 5b 41 5e 41 5f 5d e9 d1 a3 03 00 cc 48 c7 04 24 00 00
RSP: 0018:ffffc90005d277c8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 781f9740f910c200
RDX: 0000000000000000 RSI: ffffffff8b3ddd40 RDI: ffffffff8b3ddd00
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1006b5f8c6 R12: 000000000003b9ca
R13: dffffc0000000000 R14: ffff88813fffa830 R15: 0000000000001000
FS: 000055558c970500(0000) GS:ffff888126df9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe23b7a7dac CR3: 000000004e9fe000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 0000000000000009 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
rcu_lockdep_current_cpu_online+0x37/0x120 kernel/rcu/tree.c:4032
rcu_read_lock_held_common kernel/rcu/update.c:113 [inline]
rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:349
lookup_page_ext mm/page_ext.c:254 [inline]
page_ext_lookup+0xe7/0x180 mm/page_ext.c:509
page_ext_iter_begin include/linux/page_ext.h:132 [inline]
__page_table_check_zero+0x18f/0x530 mm/page_table_check.c:139
page_table_check_alloc include/linux/page_table_check.h:35 [inline]
post_alloc_hook+0x253/0x2a0 mm/page_alloc.c:1851
prep_new_page mm/page_alloc.c:1858 [inline]
get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3884
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183
alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416
alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline]
alloc_pages_noprof+0xcf/0x1e0 mm/mempolicy.c:2507
vm_area_alloc_pages mm/vmalloc.c:3647 [inline]
__vmalloc_area_node mm/vmalloc.c:3724 [inline]
__vmalloc_node_range_noprof+0x96c/0x12d0 mm/vmalloc.c:3897
vmalloc_user_noprof+0xad/0xf0 mm/vmalloc.c:4050
kcov_ioctl+0x58/0x650 kernel/kcov.c:716
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xff/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa8e13cf2cb
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007fffd737cd80 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000100000 RCX: 00007fa8e13cf2cb
RDX: 0000000000100000 RSI: ffffffff80086301 RDI: 00000000000000d7
RBP: 00007fa8e1625f40 R08: 00000000000000da R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000003 R14: 00007fffd737d0c8 R15: 0000000000000000
vkms_vblank_simulate: vblank timer overrun
vkms_vblank_simulate: vblank timer overrun
vkms_vblank_simulate: vblank timer overrun
vkms_vblank_simulate: vblank timer overrun