INFO: task syz-executor.0:7556 blocked for more than 143 seconds. Not tainted 5.15.0-rc2-next-20210924-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:28152 pid: 7556 ppid: 29666 flags:0x00024004 Call Trace: context_switch kernel/sched/core.c:4955 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6236 schedule+0xd3/0x270 kernel/sched/core.c:6315 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x176/0x280 kernel/sched/completion.c:138 io_wq_exit_workers fs/io-wq.c:1179 [inline] io_wq_put_and_exit+0x4b2/0xd20 fs/io-wq.c:1214 io_uring_clean_tctx fs/io_uring.c:9727 [inline] io_uring_cancel_generic+0x5fe/0x740 fs/io_uring.c:9807 io_uring_files_cancel include/linux/io_uring.h:16 [inline] do_exit+0x265/0x2a30 kernel/exit.c:780 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2868 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:863 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f6817fcd709 RSP: 002b:00007f6815544188 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: 0000000000002000 RBX: 00007f68180d1f60 RCX: 00007f6817fcd709 RDX: 0000000000000000 RSI: 000000000000393c RDI: 0000000000000005 RBP: 00007f6818027cb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffce93a118f R14: 00007f6815544300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8b9808a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc2-next-20210924-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:254 [inline] watchdog+0xcb7/0xed0 kernel/hung_task.c:339 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2965 Comm: systemd-journal Not tainted 5.15.0-rc2-next-20210924-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:197 Code: fd ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 00 65 8b 05 b9 2e 8c 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 40 70 02 00 a9 RSP: 0018:ffffc9000206fa18 EFLAGS: 00000216 RAX: 0000000080000000 RBX: ffffffff898cc160 RCX: ffff88807ba93a00 RDX: 0000000000000000 RSI: ffff88807ba93a00 RDI: 0000000000000003 RBP: ffffc9000206fb38 R08: 0000000000000009 R09: 0000000000000075 R10: ffffffff83f364a0 R11: 000000000000002a R12: ffffffff898cc161 R13: ffffffff898cc160 R14: 1ffff9200040df47 R15: 0000000000000075 FS: 00007fc3038728c0(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc300d1f000 CR3: 000000007acb4000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: format_decode+0x2b1/0xad0 lib/vsprintf.c:2586 vsnprintf+0x157/0x14f0 lib/vsprintf.c:2761 vscnprintf lib/vsprintf.c:2912 [inline] scnprintf+0xbb/0x140 lib/vsprintf.c:2966 info_print_ext_header.constprop.0+0x1eb/0x280 kernel/printk/printk.c:570 devkmsg_read+0x3cb/0x730 kernel/printk/printk.c:752 vfs_read+0x1b5/0x600 fs/read_write.c:483 ksys_read+0x12d/0x250 fs/read_write.c:623 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc302e01210 Code: 73 01 c3 48 8b 0d 98 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d b9 c1 20 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 4e fc ff ff 48 89 04 24 RSP: 002b:00007ffe590b6698 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007ffe590b9110 RCX: 00007fc302e01210 RDX: 0000000000002000 RSI: 00007ffe590b6f10 RDI: 0000000000000009 RBP: 0000000000000000 R08: 0000000000000008 R09: 00007ffe59131080 R10: 00007ffe591310f0 R11: 0000000000000246 R12: 00007ffe590b6f10 R13: 00007ffe590b9068 R14: 000055fcd1262958 R15: 0005ccc729af0b3c ---------------- Code disassembly (best guess), 3 bytes skipped: 0: b9 ff ff ff ff mov $0xffffffff,%ecx 5: ba 08 00 00 00 mov $0x8,%edx a: 4d 8b 03 mov (%r11),%r8 d: 48 0f bd ca bsr %rdx,%rcx 11: 49 8b 45 00 mov 0x0(%r13),%rax 15: 48 63 c9 movslq %ecx,%rcx 18: e9 64 ff ff ff jmpq 0xffffff81 1d: 0f 1f 00 nopl (%rax) 20: 65 8b 05 b9 2e 8c 7e mov %gs:0x7e8c2eb9(%rip),%eax # 0x7e8c2ee0 * 27: 89 c1 mov %eax,%ecx <-- trapping instruction 29: 48 8b 34 24 mov (%rsp),%rsi 2d: 81 e1 00 01 00 00 and $0x100,%ecx 33: 65 48 8b 14 25 40 70 mov %gs:0x27040,%rdx 3a: 02 00 3c: a9 .byte 0xa9