INFO: task syz.4.631:8461 blocked for more than 144 seconds. Not tainted 6.14.0-syzkaller-05877-g1a9239bb4253 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.631 state:D stack:27336 pid:8461 tgid:8458 ppid:5834 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5366 [inline] __schedule+0x1ac3/0x5090 kernel/sched/core.c:6747 __schedule_loop kernel/sched/core.c:6824 [inline] schedule+0x163/0x360 kernel/sched/core.c:6839 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6896 __mutex_lock_common kernel/locking/mutex.c:664 [inline] __mutex_lock+0x7fa/0x1000 kernel/locking/mutex.c:732 blk_trace_startstop+0xa7/0x790 kernel/trace/blktrace.c:700 sg_ioctl_common drivers/scsi/sg.c:1118 [inline] sg_ioctl+0x6bc/0x2ea0 drivers/scsi/sg.c:1156 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc95bd8d169 RSP: 002b:00007fc95cba9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc95bfa6080 RCX: 00007fc95bd8d169 RDX: 0000000000000000 RSI: 0000000000001274 RDI: 0000000000000003 RBP: 00007fc95be0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc95bfa6080 R15: 00007ffc1793c658 Showing all locks held in the system: 2 locks held by ksoftirqd/1/23: #0: ffff8880b8739998 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:595 #1: ffff8880b8723b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41f/0x7a0 kernel/sched/psi.c:987 1 lock held by khungtaskd/31: #0: ffffffff8eb3a260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8eb3a260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8eb3a260 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6761 2 locks held by getty/5577: #0: ffff8880353b00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000331b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x53d/0x16b0 drivers/tty/n_tty.c:2211 3 locks held by syz.4.631/8459: 1 lock held by syz.4.631/8461: #0: ffff888025e15718 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_startstop+0xa7/0x790 kernel/trace/blktrace.c:700 1 lock held by syz.5.1040/9931: #0: ffffffff8eb3f640 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3774 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-syzkaller-05877-g1a9239bb4253 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 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 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8459 Comm: syz.4.631 Not tainted 6.14.0-syzkaller-05877-g1a9239bb4253 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:56 [inline] RIP: 0010:unwind_next_frame+0x182b/0x22f0 arch/x86/kernel/unwind_orc.c:665 Code: 4c 8b 7d 38 48 8d 7d 08 48 89 f8 48 c1 e8 03 42 80 3c 20 00 74 05 e8 24 0b bb 00 4c 8b 75 08 48 8d 5d 10 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 06 0b bb 00 4d 39 fe 0f 87 b2 00 RSP: 0018:ffffc900056ff5d0 EFLAGS: 00000a06 RAX: 1ffff92000adfee2 RBX: ffffc900056ff710 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffc900056f8000 RDI: ffffc900056ff708 RBP: ffffc900056ff700 R08: ffffc900056ff790 R09: 0000000000000000 R10: ffffc900056ff750 R11: fffff52000adfeec R12: dffffc0000000000 R13: ffffc900056ff700 R14: ffffc900056f8000 R15: ffffc900056ff7a0 FS: 00007fc95cbca6c0(0000) GS:ffff888125343000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f59eb779178 CR3: 0000000058f2c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __unwind_start+0x59a/0x740 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe7/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 save_stack+0xfc/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x79/0x440 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660 relay_destroy_buf+0x112/0x3a0 kernel/relay.c:201 relay_remove_buf kernel/relay.c:221 [inline] kref_put include/linux/kref.h:65 [inline] relay_close_buf kernel/relay.c:430 [inline] relay_open+0x78d/0x960 kernel/relay.c:530 do_blk_trace_setup+0x57b/0x9c0 kernel/trace/blktrace.c:590 blk_trace_setup+0x118/0x1f0 kernel/trace/blktrace.c:632 sg_ioctl_common drivers/scsi/sg.c:1114 [inline] sg_ioctl+0xa12/0x2ea0 drivers/scsi/sg.c:1156 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc95bd8d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc95cbca038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc95bfa5fa0 RCX: 00007fc95bd8d169 RDX: 0000200000000200 RSI: 00000000c0481273 RDI: 0000000000000003 RBP: 00007fc95be0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc95bfa5fa0 R15: 00007ffc1793c658