INFO: task syz.2.788:9192 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.2.788 state:D stack:24960 pid:9192 tgid:9190 ppid:5828 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5340 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
sync_bdevs+0x27e/0x470 block/bdev.c:1304
ksys_sync fs/sync.c:105 [inline]
__ia32_sys_sync+0xc5/0x120 fs/sync.c:111
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: 0033:0x7f300cd9c629
RSP: 002b:00007f300dc3a028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f300d015fa0 RCX: 00007f300cd9c629
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f300d015fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f300d016038 R14: 00007f300d015fa0 R15: 00007fff6f67a608
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5586:
#0: ffff888032ed00a0 (&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
3 locks held by udevd/5972:
1 lock held by udevd/5988:
#0: ffff888026fb2358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
3 locks held by kworker/u8:10/7019:
#0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffffc90003147c40 ((work_completion)(©->work)){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255
#2: ffffffff8e766440 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz.2.788/9192:
#0: ffff888026fb2358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1304
4 locks held by kworker/0:6/10464:
#0: ffff88801b069148 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffffc90003337c40 ((work_completion)(&(&ssp->srcu_sup->work)->work)){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255
#2: ffffffff8e7611b8 (&ssp->srcu_sup->srcu_gp_mutex){+.+.}-{4:4}, at: srcu_advance_state kernel/rcu/srcutree.c:1836 [inline]
#2: ffffffff8e7611b8 (&ssp->srcu_sup->srcu_gp_mutex){+.+.}-{4:4}, at: process_srcu+0x6e/0x1220 kernel/rcu/srcutree.c:1996
#3: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#3: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
3 locks held by syz.6.1177/10990:
7 locks held by syz.7.1193/11031:
#0: ffffffff8e752720 (console_lock){+.+.}-{0:0}, at: do_fb_ioctl+0x5f1/0x800 drivers/video/fbdev/core/fb_chrdev.c:86
#1: ffff888026006078 (&fb_info->lock){+.+.}-{4:4}, at: lock_fb_info include/linux/fb.h:619 [inline]
#1: ffff888026006078 (&fb_info->lock){+.+.}-{4:4}, at: do_fb_ioctl+0x605/0x800 drivers/video/fbdev/core/fb_chrdev.c:87
#2: ffff88801f721a80 (&helper->lock){+.+.}-{4:4}, at: drm_fb_helper_pan_display+0xbe/0xbd0 drivers/gpu/drm/drm_fb_helper.c:1260
#3: ffff888025ffc130 (&dev->master_mutex){+.+.}-{4:4}, at: drm_master_internal_acquire+0x20/0x80 drivers/gpu/drm/drm_auth.c:435
#4: ffff88801f721898 (&client->modeset_mutex){+.+.}-{4:4}, at: drm_client_modeset_commit_locked+0x4c/0x4d0 drivers/gpu/drm/drm_client_modeset.c:1204
#5: ffffc9000f77f8d0 (crtc_ww_class_acquire){+.+.}-{0:0}, at: drm_client_modeset_commit_atomic+0x11a/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1042
#6: ffffc9000f77f8f8 (crtc_ww_class_mutex){+.+.}-{4:4}, at: drm_client_modeset_commit_atomic+0x11a/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1042
1 lock held by syz.6.1195/11033:
#0: ffffffff8e766440 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by sed/11055:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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: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: 11055 Comm: sed Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:121 [inline]
RIP: 0010:lock_acquire+0x86/0x2e0 kernel/locking/lockdep.c:5844
Code: 01 00 00 83 3d 7a 5a 70 0e 00 0f 84 c3 00 00 00 48 8b 74 24 68 4c 89 ef e8 47 19 8e 00 83 3d 60 5a 70 0e 00 0f 84 c1 00 00 00 <65> 8b 05 43 58 7b 11 85 c0 0f 85 b2 00 00 00 65 48 8b 05 8b 12 7b
RSP: 0018:ffffc9000fca6ee0 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff82202551 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff81769a62 RDI: 1ffffffff1cec05c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc9000fca7078 R11: ffffffff81b0d5b0 R12: 0000000000000002
R13: ffffffff8e7602e0 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125555000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9985416068 CR3: 0000000076328000 CR4: 00000000003526f0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5339
kmalloc_noprof include/linux/slab.h:962 [inline]
slab_free_hook mm/slub.c:2639 [inline]
slab_free mm/slub.c:6124 [inline]
kmem_cache_free+0x15b/0x630 mm/slub.c:6254
remove_vma mm/vma.c:470 [inline]
vms_complete_munmap_vmas+0x929/0xc60 mm/vma.c:1342
__mmap_complete+0x7b/0x5e0 mm/vma.c:2588
__mmap_region mm/vma.c:2768 [inline]
mmap_region+0x1d91/0x2240 mm/vma.c:2837
do_mmap+0xc39/0x10c0 mm/mmap.c:559
vm_mmap_pgoff+0x2c9/0x4f0 mm/util.c:581
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: 0033:0x7f9985710242
Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00
RSP: 002b:00007ffc45486128 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f9985417000 RCX: 00007f9985710242
RDX: 0000000000000003 RSI: 00000000000016d0 RDI: 00007f9985417000
RBP: 0000000000000032 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000000032 R11: 0000000000000206 R12: 00007ffc454861e8
R13: 00007f99856e5ab0 R14: 00007ffc454865a0 R15: 00007f9985417000