INFO: task syz-executor.5:29738 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28416 29738 3304 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x92d/0xfe0 kernel/time/timer.c:1794 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common+0x29c/0x470 kernel/sched/completion.c:115 __flush_work+0x4bb/0x8b0 kernel/workqueue.c:2926 __cancel_work_timer+0x412/0x590 kernel/workqueue.c:3013 p9_conn_destroy net/9p/trans_fd.c:904 [inline] p9_fd_close+0x305/0x520 net/9p/trans_fd.c:934 p9_client_create+0x901/0x12e0 net/9p/client.c:1084 v9fs_session_init+0x1dd/0x1770 fs/9p/v9fs.c:421 v9fs_mount+0x73/0x910 fs/9p/vfs_super.c:135 mount_fs+0xa3/0x310 fs/super.c:1261 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2492 [inline] do_mount+0x115c/0x2f50 fs/namespace.c:2822 ksys_mount+0xcf/0x130 fs/namespace.c:3038 __do_sys_mount fs/namespace.c:3052 [inline] __se_sys_mount fs/namespace.c:3049 [inline] __x64_sys_mount+0xba/0x150 fs/namespace.c:3049 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f929d9300d9 Code: Bad RIP value. RSP: 002b:00007f929be3f168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f929da501f0 RCX: 00007f929d9300d9 RDX: 0000000020000100 RSI: 0000000020000080 RDI: 0000000000000000 RBP: 00007f929d98bae9 R08: 0000000020000180 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffead96ef8f R14: 00007f929be3f300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1569: #0: 00000000cf7df676 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7823: #0: 00000000876371eb (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 1 lock held by agetty/8045: #0: 00000000874c1599 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 2 locks held by kworker/u4:2/12521: 3 locks held by kworker/u4:11/12612: #0: 0000000007f3df90 ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000f883b19e (net_cleanup_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 0000000003fc295e (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:521 2 locks held by kworker/0:7/23225: #0: 0000000083243b12 ((wq_completion)"rcu_gp"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000d40477ae ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 2 locks held by kworker/1:3/28568: #0: 00000000ad78f039 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000008a89d9b7 ((work_completion)(&m->wq)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 1 lock held by syz-executor.2/8737: #0: 00000000cba71527 (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #0: 00000000cba71527 (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x4dc/0x6f0 kernel/rcu/tree_exp.h:667 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1569 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4689 Comm: systemd-journal Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:unwind_next_frame+0xa/0x1400 arch/x86/kernel/unwind_orc.c:397 Code: 24 e8 8a e1 6e 00 48 8b 0c 24 e9 4b ff ff ff e8 1c 25 0e 00 66 66 2e 0f 1f 84 00 00 00 00 00 90 48 ba 00 00 00 00 00 fc ff df <41> 57 41 56 49 89 fe 41 55 41 54 55 53 48 81 ec e8 00 00 00 48 c7 RSP: 0018:ffff8880a0c57a08 EFLAGS: 00000206 RAX: 1ffff1101418af62 RBX: ffff8880a0c57b58 RCX: ffff8880a0c57b60 RDX: dffffc0000000000 RSI: 1ffff1101418af5d RDI: ffff8880a0c57ad8 RBP: 1ffff1101418af46 R08: 0000000000000000 R09: ffff8880a0c57b00 R10: ffff8880a0c57b37 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffed101418af5d R14: ffffed101418af5c R15: ffff8880a0c57ad8 FS: 00007f2d26e7a8c0(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2d23c09000 CR3: 00000000a11e1000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __unwind_start+0x5b8/0x960 arch/x86/kernel/unwind_orc.c:667 unwind_start arch/x86/include/asm/unwind.h:60 [inline] __save_stack_trace+0x72/0x190 arch/x86/kernel/stacktrace.c:43 save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:553 slab_post_alloc_hook mm/slab.h:445 [inline] slab_alloc mm/slab.c:3397 [inline] kmem_cache_alloc+0x110/0x370 mm/slab.c:3557 getname_flags+0xce/0x590 fs/namei.c:140 user_path_at_empty+0x2a/0x50 fs/namei.c:2609 user_path_at include/linux/namei.h:57 [inline] do_faccessat+0x248/0x7a0 fs/open.c:397 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f2d261359c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe1280ddd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffe12810e00 RCX: 00007f2d261359c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055b117d019a3 RBP: 00007ffe1280df20 R08: 000055b117cf73e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 000055b1194388a0 R15: 00007ffe1280e410