INFO: task syz-executor.0:5524 blocked for more than 143 seconds. Not tainted 6.9.0-syzkaller-12277-g56fb6f92854f #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:25424 pid:5524 tgid:5517 ppid:5456 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6837 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6894 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 bdev_release+0x184/0x700 block/bdev.c:1080 blkdev_release+0x15/0x20 block/fops.c:623 __fput+0x408/0x8b0 fs/file_table.c:422 task_work_run+0x251/0x310 kernel/task_work.c:180 get_signal+0x15e6/0x1740 kernel/signal.c:2681 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: 0033:0x7f9ca687cba9 RSP: 002b:00007f9ca75370c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f9ca699c050 RCX: 00007f9ca687cba9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f9ca68c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f9ca699c050 R15: 00007ffca686d5b8 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 3 locks held by kworker/u8:4/61: 2 locks held by getty/4842: #0: ffff88802a85d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002efe2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 1 lock held by udevd/5441: #0: ffff88802034d4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xe5/0xc60 block/bdev.c:897 1 lock held by syz-executor.0/5524: #0: ffff88802034d4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_release+0x184/0x700 block/bdev.c:1080 1 lock held by syz-executor.0/5831: #0: ffff88802034d4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xe5/0xc60 block/bdev.c:897 1 lock held by syz-executor.0/5847: #0: ffff88802034d4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xe5/0xc60 block/bdev.c:897 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 30 Comm: khungtaskd Not tainted 6.9.0-syzkaller-12277-g56fb6f92854f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 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:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xfde/0x1020 kernel/hung_task.c:379 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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: 4522 Comm: syslogd Not tainted 6.9.0-syzkaller-12277-g56fb6f92854f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:unwind_next_frame+0x1e0/0x2a00 arch/x86/kernel/unwind_orc.c:494 Code: 24 70 4c 89 6c 24 48 0f 84 41 01 00 00 48 c7 c3 00 00 00 81 48 89 ef 48 c7 c6 00 00 00 81 e8 07 36 55 00 49 c7 c6 00 00 c0 8b <48> 89 ef 48 c7 c6 00 00 c0 8b e8 f1 35 55 00 48 39 dd 48 89 6c 24 RSP: 0018:ffffc90009b1f368 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffffffff81000000 RCX: ffff88807ed7da00 RDX: ffffc90009b1f475 RSI: ffffffff81000000 RDI: ffffffff81fb9b1e RBP: ffffffff81fb9b1e R08: ffffffff8140e139 R09: ffffc90009b1f530 R10: 0000000000000003 R11: ffffffff8181ce30 R12: ffffc90009b1f440 R13: ffffc90009b1f490 R14: ffffffff8bc00000 R15: ffffffff81fb9b1f FS: 00007f1a91f26380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563d359f2680 CR3: 000000002cdda000 CR4: 0000000000350ef0 Call Trace: arch_stack_walk+0x151/0x1b0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2195 [inline] slab_free mm/slub.c:4436 [inline] kfree+0x149/0x360 mm/slub.c:4557 skb_kfree_head net/core/skbuff.c:1069 [inline] skb_free_head net/core/skbuff.c:1081 [inline] skb_release_data+0x676/0x880 net/core/skbuff.c:1108 skb_release_all net/core/skbuff.c:1173 [inline] __kfree_skb net/core/skbuff.c:1187 [inline] consume_skb+0xb1/0x160 net/core/skbuff.c:1409 __unix_dgram_recvmsg+0xcea/0x12f0 net/unix/af_unix.c:2469 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg+0x231/0x280 net/socket.c:1068 sock_read_iter+0x2ca/0x3e0 net/socket.c:1138 new_sync_read fs/read_write.c:395 [inline] vfs_read+0x9c6/0xbd0 fs/read_write.c:476 ksys_read+0x1a0/0x2c0 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1a9207ab6a Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffefeec65b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f1a9207ab6a RDX: 00000000000000ff RSI: 00005611651ca950 RDI: 0000000000000000 RBP: 00005611651ca910 R08: 0000000000000001 R09: 0000000000000000 R10: 00007f1a922193a3 R11: 0000000000000246 R12: 00005611651ca99a R13: 00005611651ca950 R14: 0000000000000000 R15: 00007f1a9225da80