INFO: task syz-executor158:8221 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-executor158 D27400 8221 8138 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:899 [inline] p9_fd_close+0x29c/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: 0033:0x7f3351de8359 Code: Bad RIP value. RSP: 002b:00007f3351d74278 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f3351e6d4f0 RCX: 00007f3351de8359 RDX: 0000000020000080 RSI: 0000000020000300 RDI: 0000000000000000 RBP: 00007f3351e3a0bc R08: 0000000020000740 R09: 65732f636f72702f R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3351d74280 R13: 7277732f7665642f R14: 64663d736e617274 R15: 00007f3351e6d4f8 Showing all locks held in the system: 2 locks held by kworker/0:1/14: #0: 00000000e305f09a ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000003e9ac0c2 ((work_completion)(&m->rq)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 1 lock held by khungtaskd/1570: #0: 00000000eca63a1d (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7824: #0: 0000000040d68714 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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: 4690 Comm: systemd-journal Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_kcov_mode kernel/kcov.c:67 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x14/0x50 kernel/kcov.c:101 Code: 35 00 e9 23 fe ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 34 24 65 48 8b 04 25 c0 df 01 00 65 8b 15 cc 59 9f 7e <81> e2 00 01 1f 00 75 2b 8b 90 60 13 00 00 83 fa 02 75 20 48 8b 88 RSP: 0018:ffff8880a139fa28 EFLAGS: 00000246 RAX: ffff8880a1394500 RBX: dffffc0000000000 RCX: ffffffff816c5cc8 RDX: 0000000080000000 RSI: ffffffff816c36e5 RDI: ffffc90001b12072 RBP: ffff8880a139fb00 R08: 0000000000000000 R09: 0000000000000015 R10: 0000000000000006 R11: 0000000000000000 R12: ffffffff886fb460 R13: ffffed1014273f62 R14: ffffc90001b121e0 R15: 0000000040000000 FS: 00007f293b3f08c0(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f29387c9000 CR3: 00000000a1186000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ___bpf_prog_run+0x45/0x4e80 kernel/bpf/core.c:1065 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: e9 23 fe ff ff jmpq 0xfffffe28 5: 90 nop 6: 90 nop 7: 90 nop 8: 90 nop 9: 90 nop a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 48 8b 34 24 mov (%rsp),%rsi 18: 65 48 8b 04 25 c0 df mov %gs:0x1dfc0,%rax 1f: 01 00 21: 65 8b 15 cc 59 9f 7e mov %gs:0x7e9f59cc(%rip),%edx # 0x7e9f59f4 * 28: 81 e2 00 01 1f 00 and $0x1f0100,%edx <-- trapping instruction 2e: 75 2b jne 0x5b 30: 8b 90 60 13 00 00 mov 0x1360(%rax),%edx 36: 83 fa 02 cmp $0x2,%edx 39: 75 20 jne 0x5b 3b: 48 rex.W 3c: 8b .byte 0x8b 3d: 88 .byte 0x88