INFO: task syz-executor.0:5029 blocked for more than 143 seconds. Not tainted 6.4.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:20024 pid:5029 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0x187b/0x4900 kernel/sched/core.c:6669 schedule+0xc3/0x180 kernel/sched/core.c:6745 wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:192 sync_inodes_sb+0x297/0xab0 fs/fs-writeback.c:2730 sync_filesystem+0x16f/0x220 fs/sync.c:64 generic_shutdown_super+0x6f/0x340 fs/super.c:473 kill_block_super+0x84/0xf0 fs/super.c:1407 deactivate_locked_super+0xa4/0x110 fs/super.c:331 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1177 task_work_run+0x24a/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xd9/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x64/0x280 kernel/entry/common.c:297 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f66e428d5d7 RSP: 002b:00007fffd8c94f88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f66e428d5d7 RDX: 00007fffd8c9505b RSI: 000000000000000a RDI: 00007fffd8c95050 RBP: 00007fffd8c95050 R08: 00000000ffffffff R09: 00007fffd8c94e20 R10: 0000555555816893 R11: 0000000000000246 R12: 00007f66e42e6cdc R13: 00007fffd8c96110 R14: 0000555555816810 R15: 00007fffd8c96150 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8cf276f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:518 1 lock held by rcu_tasks_trace/14: #0: ffffffff8cf27ab0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:518 1 lock held by khungtaskd/28: #0: ffffffff8cf27520 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/u4:2/33: #0: ffff888146255938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2378 #1: ffffc90000a9fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2380 2 locks held by getty/4746: #0: ffff88802d2aa098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900015902f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ab/0x1db0 drivers/tty/n_tty.c:2176 2 locks held by syz-executor.0/5029: #0: ffff888038ace0e0 (&type->s_umount_key#72){+.+.}-{3:3}, at: deactivate_super+0xad/0xf0 fs/super.c:361 #1: ffff888140bd67d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff888140bd67d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x278/0xab0 fs/fs-writeback.c:2728 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.4.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x187/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xec2/0xf00 kernel/hung_task.c:379 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4438 Comm: klogd Not tainted 6.4.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 RIP: 0010:qlist_free_all+0x1a/0x60 mm/kasan/quarantine.c:185 Code: 00 00 89 d8 5b c3 66 2e 0f 1f 84 00 00 00 00 00 41 57 41 56 41 54 53 48 8b 1f 48 85 db 74 47 49 89 f7 49 89 fe eb 13 4c 8b 23 <48> 89 df e8 be 05 00 00 4c 89 e3 4d 85 e4 74 15 4c 89 fe 4d 85 ff RSP: 0018:ffffc9000315f608 EFLAGS: 00000286 RAX: ffff888012442140 RBX: ffff888086668000 RCX: ffffea0002199a00 RDX: ffffea0000000000 RSI: ffff888012442140 RDI: 0000000000000000 RBP: ffff888021114b40 R08: ffffffff813dc41c R09: 00000000800c0000 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888017376000 R13: 0000000000000001 R14: ffffc9000315f630 R15: 0000000000000000 FS: 00007f37ce496380(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c0002f8000 CR3: 0000000022dc0000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kasan_quarantine_reduce+0x14b/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x23/0x70 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook+0x68/0x3a0 mm/slab.h:711 slab_alloc_node mm/slub.c:3451 [inline] __kmem_cache_alloc_node+0x14c/0x290 mm/slub.c:3490 __do_kmalloc_node mm/slab_common.c:965 [inline] __kmalloc_node_track_caller+0xa5/0x230 mm/slab_common.c:986 kmalloc_reserve+0xfe/0x240 net/core/skbuff.c:585 __alloc_skb+0x1b1/0x420 net/core/skbuff.c:654 alloc_skb include/linux/skbuff.h:1288 [inline] alloc_skb_with_frags+0xa8/0x750 net/core/skbuff.c:6380 sock_alloc_send_pskb+0x919/0xa50 net/core/sock.c:2729 unix_dgram_sendmsg+0x5b5/0x2050 net/unix/af_unix.c:1944 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] __sys_sendto+0x475/0x630 net/socket.c:2144 __do_sys_sendto net/socket.c:2156 [inline] __se_sys_sendto net/socket.c:2152 [inline] __x64_sys_sendto+0xde/0xf0 net/socket.c:2152 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f37ce5f89b5 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:00007fffe963ffc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f37ce5f89b5 RDX: 0000000000000046 RSI: 00005612d6fef1d0 RDI: 0000000000000003 RBP: 00005612d6fe7910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013 R13: 00007f37ce786212 R14: 00007fffe96400c8 R15: 0000000000000000