INFO: task syz-executor.0:5500 blocked for more than 143 seconds. Not tainted 6.9.0-rc5-syzkaller-00036-g9d1ddab261f3 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:26192 pid:5500 tgid:5498 ppid:5436 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x1796/0x4a00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6895 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 bdev_release+0x1c8/0x720 block/bdev.c:1059 blkdev_release+0x15/0x20 block/fops.c:628 __fput+0x429/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:180 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+0x102/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7c4a87cae9 RSP: 002b:00007f7c4b6a00c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f7c4a99bf80 RCX: 00007f7c4a87cae9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f7c4a8c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f7c4a99bf80 R15: 00007ffd432e21a8 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by getty/4827: #0: ffff88802b1f60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 1 lock held by udevd/5420: #0: ffff8880208454c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xdd/0xcb0 block/bdev.c:877 1 lock held by syz-executor.0/5500: #0: ffff8880208454c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_release+0x1c8/0x720 block/bdev.c:1059 1 lock held by syz-executor.0/5808: #0: ffff8880208454c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xdd/0xcb0 block/bdev.c:877 1 lock held by syz-executor.0/5825: #0: ffff8880208454c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xdd/0xcb0 block/bdev.c:877 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.9.0-rc5-syzkaller-00036-g9d1ddab261f3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xfde/0x1020 kernel/hung_task.c:380 kthread+0x2f0/0x390 kernel/kthread.c:388 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 PID: 4514 Comm: klogd Not tainted 6.9.0-rc5-syzkaller-00036-g9d1ddab261f3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:check_wait_context kernel/locking/lockdep.c:4789 [inline] RIP: 0010:__lock_acquire+0x717/0x1fd0 kernel/locking/lockdep.c:5087 Code: 10 84 c0 0f 85 1f 13 00 00 48 8b 04 24 8b 28 41 89 ec ff cd 0f 88 a5 00 00 00 89 eb 83 fd 31 73 7b 48 8d 04 9b 48 8d 5c c6 20 <48> 89 d8 48 c1 e8 03 0f b6 04 10 84 c0 75 18 8b 1b 41 0f b6 04 16 RSP: 0018:ffffc90004277770 EFLAGS: 00000097 RAX: 0000000000000000 RBX: ffff88807f0b0af8 RCX: 0000000000000002 RDX: dffffc0000000000 RSI: ffff88807f0b0ad8 RDI: ffffffff92f005a0 RBP: 0000000000000000 R08: ffffffff92f005a7 R09: 1ffffffff25e00b4 R10: dffffc0000000000 R11: fffffbfff25e00b5 R12: 0000000000000001 R13: ffff88807f0b0000 R14: 1ffff1100fe16164 R15: ffff88807f0b0b20 FS: 00007fd288357380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005625f46dc680 CR3: 000000007fa28000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 skb_queue_tail+0x36/0x120 net/core/skbuff.c:3973 unix_dgram_sendmsg+0x1450/0x1f80 net/unix/af_unix.c:2157 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 __sys_sendto+0x3a4/0x4f0 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2199 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd2884b99b5 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:00007fff68f553a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fd2884b99b5 RDX: 000000000000008b RSI: 000055af90fa16b0 RDI: 0000000000000003 RBP: 000055af90f9c910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013 R13: 00007fd288647212 R14: 00007fff68f554a8 R15: 0000000000000000