INFO: task syz.1.399:7268 blocked for more than 143 seconds.
Not tainted 6.15.0-rc6-syzkaller-00080-g1a80a098c606 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.399 state:D stack:23608 pid:7268 tgid:7267 ppid:5848 task_flags:0x400140 flags:0x20004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
__mutex_lock_common kernel/locking/mutex.c:678 [inline]
__mutex_lock+0x724/0xe80 kernel/locking/mutex.c:746
compat_blk_trace_setup kernel/trace/blktrace.c:666 [inline]
blk_trace_ioctl+0x33f/0x430 kernel/trace/blktrace.c:735
compat_blkdev_ioctl+0x442/0x780 block/ioctl.c:753
__do_compat_sys_ioctl fs/ioctl.c:1004 [inline]
__se_compat_sys_ioctl fs/ioctl.c:947 [inline]
__ia32_compat_sys_ioctl+0x554/0x840 fs/ioctl.c:947
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xb4/0x110 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf706e539
RSP: 002b:00000000f505e55c EFLAGS: 00000206 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000c0401273
RDX: 0000000080000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
2 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/31:
#0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
3 locks held by kworker/1:1/49:
#0: ffff88801a080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc90000ba7c60 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90000ba7c60 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8df437b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
#2: ffffffff8df437b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998
2 locks held by getty/5592:
#0: ffff88802fd3f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900030062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz.1.399/7268:
#0: ffff8880243ffe18 (&q->debugfs_mutex){+.+.}-{4:4}, at: compat_blk_trace_setup kernel/trace/blktrace.c:666 [inline]
#0: ffff8880243ffe18 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x33f/0x430 kernel/trace/blktrace.c:735
2 locks held by syz.4.400/7270:
1 lock held by syz.3.760/8654:
2 locks held by syz.3.760/8656:
#0: ffff88815c5210a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffff88815c521130 (&tty->atomic_write_lock){+.+.}-{4:4}, at: tty_write_lock drivers/tty/tty_io.c:948 [inline]
#1: ffff88815c521130 (&tty->atomic_write_lock){+.+.}-{4:4}, at: iterate_tty_write drivers/tty/tty_io.c:967 [inline]
#1: ffff88815c521130 (&tty->atomic_write_lock){+.+.}-{4:4}, at: file_tty_write+0x1d6/0x990 drivers/tty/tty_io.c:1090
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-00080-g1a80a098c606 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
<TASK>
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:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8649 Comm: syz.0.759 Not tainted 6.15.0-rc6-syzkaller-00080-g1a80a098c606 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:unwind_next_frame+0x116b/0x2390 arch/x86/kernel/unwind_orc.c:-1
Code: 4c 89 ef e8 e7 10 b0 00 48 8b 14 24 4d 89 65 00 41 0f b6 04 2f 84 c0 0f 85 f9 0f 00 00 c6 03 00 4c 8b 64 24 10 4c 8b 7c 24 28 <48> 8b 44 24 40 0f b6 04 28 84 c0 0f 85 8a 0d 00 00 41 0f b6 04 2f
RSP: 0018:ffffc90003e97118 EFLAGS: 00000246
RAX: ffffc90003e97298 RBX: ffffc90003e97280 RCX: 0000000000000000
RDX: ffffffff900d47dc RSI: 0000000000000000 RDI: ffffc90003e972a8
RBP: dffffc0000000000 R08: ffffc90003e972a7 R09: 0000000000000000
R10: ffffc90003e97298 R11: fffff520007d2e55 R12: ffffc90003e97248
R13: ffffc90003e97298 R14: ffffc90003e97248 R15: 1ffffffff201a8fb
FS: 0000000000000000(0000) GS:ffff8881260c7000(0000) knlGS:0000000000000000
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000057ab299c CR3: 0000000031db8000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:548
slab_free_hook mm/slub.c:2341 [inline]
slab_free mm/slub.c:4642 [inline]
kmem_cache_free+0x2ee/0x3f0 mm/slub.c:4744
anon_vma_free mm/rmap.c:137 [inline]
__put_anon_vma+0x12b/0x2d0 mm/rmap.c:2756
put_anon_vma include/linux/rmap.h:117 [inline]
unlink_anon_vmas+0x503/0x670 mm/rmap.c:444
free_pgtables+0x224/0x710 mm/memory.c:370
exit_mmap+0x46c/0xba0 mm/mmap.c:1295
__mmput+0x118/0x420 kernel/fork.c:1379
exit_mm+0x1da/0x2c0 kernel/exit.c:589
do_exit+0x859/0x2550 kernel/exit.c:940
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x125e/0x1310 kernel/signal.c:3034
arch_do_signal_or_restart+0x95/0x780 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x8b/0x120 kernel/entry/common.c:218
__do_fast_syscall_32+0xc1/0x110 arch/x86/entry/syscall_32.c:309
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf70be539
Code: Unable to access opcode bytes at 0xf70be50f.
RSP: 002b:00000000f50ac484 EFLAGS: 00000206 ORIG_RAX: 0000000000000036
RAX: fffffffffffffffc RBX: 000000000000000c RCX: 0000000080085502
RDX: 00000000f50ad510 RSI: 00000000f7422ff4 RDI: 00000000f50ac518
RBP: 00000000f7422ff4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>