INFO: task syz-executor.1:16615 blocked for more than 143 seconds. Not tainted 5.15.0-next-20211109-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.1 state:D stack:28040 pid:16615 ppid: 9534 flags:0x00024004 Call Trace: context_switch kernel/sched/core.c:4984 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6265 schedule+0xd2/0x260 kernel/sched/core.c:6338 io_uring_cancel_generic+0x53d/0x690 fs/io_uring.c:9846 io_uring_files_cancel include/linux/io_uring.h:16 [inline] do_exit+0x60c/0x2b40 kernel/exit.c:787 do_group_exit+0x125/0x310 kernel/exit.c:929 get_signal+0x47d/0x2220 kernel/signal.c:2830 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 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: 0033:0x7fcca334dae7 RSP: 002b:00007fcca08c3218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 00000000000000ca RBX: 00007fcca3460f68 RCX: 00007fcca334dae9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fcca3460f68 RBP: 00007fcca3460f60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcca3460f6c R13: 00007ffe1671d45f R14: 00007fcca08c3300 R15: 0000000000022000 Showing all locks held in the system: 5 locks held by kworker/u4:1/10: 1 lock held by khungtaskd/27: #0: ffffffff8bb83a60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6220: 2 locks held by kworker/u4:8/9371: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.0-next-20211109-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: 6220 Comm: in:imklog Not tainted 5.15.0-next-20211109-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:check_preemption_disabled+0x46/0x170 lib/smp_processor_id.c:19 Code: 8b 1d 0e a6 b2 76 81 e3 ff ff ff 7f 31 ff 89 de 0f 1f 44 00 00 85 db 74 11 0f 1f 44 00 00 44 89 e0 5b 5d 41 5c 41 5d 41 5e c3 <0f> 1f 44 00 00 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de 0f 1f 44 00 RSP: 0018:ffffc9000bc67a08 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff8a04a6a0 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff81ac431f R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff89ac0c20 R14: 00000000ffffffff R15: 00007f1ddc50fda0 FS: 00007f1ddc530700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feeac3d8000 CR3: 0000000070f3f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:433 [inline] lock_is_held_type+0x63/0x140 kernel/locking/lockdep.c:5679 lock_is_held include/linux/lockdep.h:283 [inline] __might_resched+0x3a/0x2c0 kernel/sched/core.c:9516 __might_fault+0x6c/0x170 mm/memory.c:5254 _copy_to_user+0x27/0x150 lib/usercopy.c:28 copy_to_user include/linux/uaccess.h:200 [inline] syslog_print+0x384/0x580 kernel/printk/printk.c:1556 do_syslog.part.0+0x202/0x640 kernel/printk/printk.c:1658 do_syslog+0x49/0x60 kernel/printk/printk.c:1643 kmsg_read+0x90/0xb0 fs/proc/kmsg.c:40 pde_read fs/proc/inode.c:311 [inline] proc_reg_read+0x119/0x300 fs/proc/inode.c:321 vfs_read+0x1b5/0x600 fs/read_write.c:479 ksys_read+0x12d/0x250 fs/read_write.c:619 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: 0033:0x7f1ddeb7322d Code: 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 b8 00 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 97 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007f1ddc50f580 EFLAGS: 00000293 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1ddeb7322d RDX: 0000000000001fa0 RSI: 00007f1ddc50fda0 RDI: 0000000000000004 RBP: 000055db3f3f89d0 R08: 0000000000000000 R09: 0000000000000000 R10: 2ce33e6c02ce33e7 R11: 0000000000000293 R12: 00007f1ddc50fda0 R13: 0000000000001fa0 R14: 0000000000001f9f R15: 00007f1ddc50fe03 ---------------- Code disassembly (best guess): 0: 8b 1d 0e a6 b2 76 mov 0x76b2a60e(%rip),%ebx # 0x76b2a614 6: 81 e3 ff ff ff 7f and $0x7fffffff,%ebx c: 31 ff xor %edi,%edi e: 89 de mov %ebx,%esi 10: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 15: 85 db test %ebx,%ebx 17: 74 11 je 0x2a 19: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 1e: 44 89 e0 mov %r12d,%eax 21: 5b pop %rbx 22: 5d pop %rbp 23: 41 5c pop %r12 25: 41 5d pop %r13 27: 41 5e pop %r14 29: c3 retq * 2a: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) <-- trapping instruction 2f: 9c pushfq 30: 5b pop %rbx 31: 81 e3 00 02 00 00 and $0x200,%ebx 37: 31 ff xor %edi,%edi 39: 48 89 de mov %rbx,%rsi 3c: 0f .byte 0xf 3d: 1f (bad) 3e: 44 rex.R