INFO: task syz-executor.0:5458 blocked for more than 143 seconds. Not tainted 6.9.0-rc5-syzkaller-00053-ge33c4963bf53 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:28256 pid:5458 tgid:5457 ppid:5430 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0xe7/0x350 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+0x5b8/0x9c0 kernel/locking/mutex.c:752 bdev_release+0x166/0x710 block/bdev.c:1059 blkdev_release+0x15/0x20 block/fops.c:628 __fput+0x270/0xb80 fs/file_table.c:422 task_work_run+0x14e/0x250 kernel/task_work.c:180 get_signal+0x1ca/0x2710 kernel/signal.c:2683 arch_do_signal_or_restart+0x90/0x7e0 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+0x14a/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5c52879a29 RSP: 002b:00007f5c5394f0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f5c5298bf80 RCX: 00007f5c52879a29 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f5c528d52d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f5c5298bf80 R15: 00007ffcbffa3bd8 Showing all locks held in the system: 2 locks held by kworker/0:0/7: #0: ffff8880b943ea58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559 #1: ffff8880b9428a08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2d9/0x900 kernel/sched/psi.c:988 1 lock held by khungtaskd/29: #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614 1 lock held by syslogd/4507: #0: ffff8880b953ea58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559 2 locks held by getty/4828: #0: ffff88802a9130a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002efe2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2201 1 lock held by udevd/5428: #0: ffff88801ffab4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0x43c/0xe90 block/bdev.c:877 1 lock held by syz-executor.0/5458: #0: ffff88801ffab4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_release+0x166/0x710 block/bdev.c:1059 1 lock held by syz-executor.0/5487: #0: ffff88801ffab4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0x43c/0xe90 block/bdev.c:877 1 lock held by syz-executor.0/5510: #0: ffff88801ffab4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0x43c/0xe90 block/bdev.c:877 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.9.0-rc5-syzkaller-00053-ge33c4963bf53 #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+0x116/0x1f0 lib/dump_stack.c:114 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 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+0xf86/0x1240 kernel/hung_task.c:380 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4514 Comm: klogd Not tainted 6.9.0-rc5-syzkaller-00053-ge33c4963bf53 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline] RIP: 0010:stack_access_ok+0x6f/0x270 arch/x86/kernel/unwind_orc.c:393 Code: 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02 00 0f 85 c7 01 00 00 48 8b 43 10 48 89 da 48 c1 ea 03 48 89 04 24 <48> b8 00 00 00 00 00 fc ff df 0f b6 04 02 84 c0 74 08 3c 03 0f 8e RSP: 0018:ffffc90002f87440 EFLAGS: 00000a02 RAX: ffffc90002f88000 RBX: ffffc90002f87508 RCX: 0000000000000001 RDX: 1ffff920005f0ea1 RSI: ffffffff813d1472 RDI: ffffc90002f87508 RBP: ffffc90002f87ec0 R08: 0000000000000001 R09: 0000000000000004 R10: 0000000000000001 R11: 0000000000000001 R12: ffffc90002f87510 R13: ffffc90002f87518 R14: ffffc90002f80000 R15: 0000000000000001 FS: 00007f49580e6380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c408843600 CR3: 000000006268c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline] unwind_next_frame+0x1b94/0x23a0 arch/x86/kernel/unwind_orc.c:648 arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:3966 [inline] __kmalloc_node_track_caller+0x220/0x470 mm/slub.c:3986 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:599 __alloc_skb+0x164/0x380 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1313 [inline] alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6504 sock_alloc_send_pskb+0x7f1/0x980 net/core/sock.c:2795 unix_dgram_sendmsg+0x4b9/0x1b10 net/unix/af_unix.c:2019 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x47f/0x4e0 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2199 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f49582489b5 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:00007ffc4207e868 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f49582489b5 RDX: 0000000000000049 RSI: 000056123af0a1e0 RDI: 0000000000000003 RBP: 000056123af032c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013 R13: 00007f49583d6212 R14: 00007ffc4207e968 R15: 0000000000000000