INFO: task syz-executor.2:6015 blocked for more than 143 seconds. Not tainted 6.6.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:28400 pid:6015 ppid:5051 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0xee1/0x5a10 kernel/sched/core.c:6695 schedule+0xe7/0x1b0 kernel/sched/core.c:6771 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6830 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x969/0x1340 kernel/locking/mutex.c:747 blkdev_put+0xb0/0x8e0 block/bdev.c:884 blkdev_release+0x82/0xa0 block/fops.c:604 __fput+0x3f7/0xa70 fs/file_table.c:384 task_work_run+0x14d/0x240 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x215/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f4dcc27cae9 RSP: 002b:00007f4dcd0430c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f4dcc39bf80 RCX: 00007f4dcc27cae9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f4dcc2c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f4dcc39bf80 R15: 00007ffd387cd6c8 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cbab2a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:303 [inline] #0: ffffffff8cbab2a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:749 [inline] #0: ffffffff8cbab2a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6613 2 locks held by getty/4791: #0: ffff88802a1ba0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900031232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc5/0x1480 drivers/tty/n_tty.c:2206 2 locks held by kworker/u4:15/6726: #0: ffff8880b983c718 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:558 #1: ffff8880b9828888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x20c/0x900 kernel/sched/psi.c:987 1 lock held by udevd/694: #0: ffff88801cc104c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x4f0/0xb20 block/bdev.c:786 1 lock held by syz-executor.2/6015: #0: ffff88801cc104c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xb0/0x8e0 block/bdev.c:884 1 lock held by syz-executor.2/6112: #0: ffff88801cc104c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x4f0/0xb20 block/bdev.c:786 1 lock held by syz-executor.2/6170: #0: ffff88801cc104c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x4f0/0xb20 block/bdev.c:786 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.6.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x277/0x380 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x299/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf87/0x1210 kernel/hung_task.c:379 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4477 Comm: klogd Not tainted 6.6.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 RIP: 0010:select_task_rq_fair+0xb2/0x4100 kernel/sched/fair.c:7882 Code: 2c 48 89 f8 48 c1 e8 03 0f b6 14 10 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 9d 39 00 00 8b 45 2c c1 e8 02 83 f0 01 <83> e0 01 89 44 24 48 e8 b2 57 e1 08 48 c7 c2 58 63 ce 8e 89 44 24 RSP: 0018:ffffc9000317f7d8 EFLAGS: 00000006 RAX: 0000000000100041 RBX: 1ffff9200062ff24 RCX: 1ffffffff18b8d36 RDX: 0000000000000000 RSI: 0000000000000010 RDI: ffff88807d1b802c RBP: ffff88807d1b8000 R08: 0000000000000001 R09: fffffbfff1d9c5ba R10: ffffffff8ece2dd7 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: ffff88807e314568 R15: ffff88807e313b94 FS: 00007f75f8675380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2c723000 CR3: 000000002971c000 CR4: 0000000000350ef0 Call Trace: select_task_rq kernel/sched/core.c:3631 [inline] try_to_wake_up+0x620/0x15b0 kernel/sched/core.c:4331 autoremove_wake_function+0x16/0x150 kernel/sched/wait.c:424 receiver_wake_function+0x53/0x80 net/core/datagram.c:81 __wake_up_common+0x140/0x5a0 kernel/sched/wait.c:107 __wake_up_common_lock+0xd6/0x140 kernel/sched/wait.c:138 sock_def_readable+0x156/0x750 net/core/sock.c:3324 unix_dgram_sendmsg+0x1133/0x1c30 net/unix/af_unix.c:2093 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xd5/0x180 net/socket.c:745 __sys_sendto+0x255/0x340 net/socket.c:2194 __do_sys_sendto net/socket.c:2206 [inline] __se_sys_sendto net/socket.c:2202 [inline] __x64_sys_sendto+0xe0/0x1b0 net/socket.c:2202 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f75f87d79b5 Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffd1b06ec98 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f75f87d79b5 RDX: 0000000000000074 RSI: 0000557eebb0f1e0 RDI: 0000000000000003 RBP: 0000557eebb08910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013 R13: 00007f75f8965212 R14: 00007ffd1b06ed98 R15: 0000000000000000