Hello, syzbot found the following issue on: HEAD commit: 92edc4ae Add linux-next specific files for 20201113 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=15982d72500000 kernel config: https://syzkaller.appspot.com/x/.config?x=79ad4f8ad2d96176 dashboard link: https://syzkaller.appspot.com/bug?extid=f02b92479b7065807a2a compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=116fb7be500000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f02b92479b7065807a2a@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz-executor.0:26152 can't die for more than 143 seconds. task:syz-executor.0 state:D stack:28544 pid:26152 ppid: 8500 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4269 [inline] __schedule+0x890/0x2030 kernel/sched/core.c:5019 schedule+0xcf/0x270 kernel/sched/core.c:5098 perf_event_free_task+0x514/0x6b0 kernel/events/core.c:12605 copy_process+0x48e0/0x6f90 kernel/fork.c:2360 kernel_clone+0xe7/0xab0 kernel/fork.c:2462 __do_sys_clone+0xc8/0x110 kernel/fork.c:2579 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 Code: Unable to access opcode bytes at RIP 0x45de8f. RSP: 002b:00007ffb605e6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000002040 RCX: 000000000045deb9 RDX: 9999999999999999 RSI: 0000000000000000 RDI: 0000000000000100 RBP: 000000000118bf70 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007fff8d97524f R14: 00007ffb605e79c0 R15: 000000000118bf2c INFO: task syz-executor.0:26152 blocked for more than 143 seconds. Not tainted 5.10.0-rc3-next-20201113-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:28544 pid:26152 ppid: 8500 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4269 [inline] __schedule+0x890/0x2030 kernel/sched/core.c:5019 schedule+0xcf/0x270 kernel/sched/core.c:5098 perf_event_free_task+0x514/0x6b0 kernel/events/core.c:12605 copy_process+0x48e0/0x6f90 kernel/fork.c:2360 kernel_clone+0xe7/0xab0 kernel/fork.c:2462 __do_sys_clone+0xc8/0x110 kernel/fork.c:2579 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 Code: Unable to access opcode bytes at RIP 0x45de8f. RSP: 002b:00007ffb605e6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000002040 RCX: 000000000045deb9 RDX: 9999999999999999 RSI: 0000000000000000 RDI: 0000000000000100 RBP: 000000000118bf70 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007fff8d97524f R14: 00007ffb605e79c0 R15: 000000000118bf2c Showing all locks held in the system: 1 lock held by khungtaskd/1567: #0: ffffffff8b339ce0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6252 1 lock held by in:imklog/8178: #0: ffff88801c937c70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:932 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1567 Comm: khungtaskd Not tainted 5.10.0-rc3-next-20201113-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xd89/0xf30 kernel/hung_task.c:338 kthread+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x1c9/0x250 drivers/acpi/processor_idle.c:517 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
