INFO: task syz.1.124:5818 blocked for more than 143 seconds. Not tainted 6.11.0-rc4-syzkaller-00635-g2c163922de69 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.124 state:D stack:24672 pid:5818 tgid:5818 ppid:5235 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 pipe_release+0x4e/0x330 fs/pipe.c:727 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3879f79e79 RSP: 002b:00007ffdc3104b48 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f387a117a80 RCX: 00007f3879f79e79 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f387a117a80 R08: 0000000000000006 R09: 00007ffdc3104e2f R10: 00000000003ffc88 R11: 0000000000000246 R12: 000000000001861c R13: 00007ffdc3104c40 R14: 00007ffdc3104c60 R15: ffffffffffffffff Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6626 1 lock held by dhcpcd/4895: 2 locks held by getty/4986: #0: ffff88802f6010a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ac/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5238: 3 locks held by kworker/u8:11/5408: 1 lock held by syz.1.124/5818: #0: ffff888029ec9868 (&pipe->mutex){+.+.}-{3:3}, at: pipe_release+0x4e/0x330 fs/pipe.c:727 1 lock held by syz.1.124/5819: #0: ffff888029ec9868 (&pipe->mutex){+.+.}-{3:3}, at: splice_file_to_pipe+0x2e/0x500 fs/splice.c:1292 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc4-syzkaller-00635-g2c163922de69 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5666 Comm: syz-executor Not tainted 6.11.0-rc4-syzkaller-00635-g2c163922de69 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:147 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xae/0x140 kernel/locking/spinlock.c:194 Code: 00 02 00 00 74 05 e8 11 69 d9 f5 4c 89 f3 48 c1 eb 03 42 80 3c 23 00 74 08 4c 89 f7 e8 3b 47 39 f6 48 c7 44 24 20 00 00 00 00 <9c> 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 2e 46 39 f6 f6 44 RSP: 0018:ffffc90014a478e0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 1ffff92002948f20 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff9515c778 RBP: ffffc90014a47970 R08: ffffffff9515c77b R09: 1ffffffff2a2b8ef R10: dffffc0000000000 R11: fffffbfff2a2b8f0 R12: dffffc0000000000 R13: 1ffff92002948f1c R14: ffffc90014a47900 R15: 0000000000000046 FS: 0000555575b03500(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffda5aa3b80 CR3: 0000000058d28000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __debug_check_no_obj_freed lib/debugobjects.c:999 [inline] debug_check_no_obj_freed+0x561/0x580 lib/debugobjects.c:1020 slab_free_hook mm/slub.c:2219 [inline] slab_free mm/slub.c:4473 [inline] kmem_cache_free+0x10f/0x350 mm/slub.c:4548 __sigqueue_free kernel/signal.c:451 [inline] collect_signal kernel/signal.c:594 [inline] __dequeue_signal+0x4ac/0x5c0 kernel/signal.c:616 dequeue_signal+0x169/0x5a0 kernel/signal.c:639 get_signal+0x602/0x1740 kernel/signal.c:2796 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4aba778b0a Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 13 8c 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 73 8c 02 00 8b 44 24 RSP: 002b:00007ffea2e08090 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007f4aba778b0a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f4aba7e8a01 R08: 0000000000000000 R09: 00007ffea2e07ed7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 00007ffea2e080d0 R14: 00007f4abb444620 R15: 0000000000000003