From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f197.google.com ([209.85.223.197]:53830 "EHLO mail-io0-f197.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933129AbeGJKaC (ORCPT ); Tue, 10 Jul 2018 06:30:02 -0400 Received: by mail-io0-f197.google.com with SMTP id o24-v6so18905993iob.20 for ; Tue, 10 Jul 2018 03:30:02 -0700 (PDT) MIME-Version: 1.0 Date: Tue, 10 Jul 2018 03:30:02 -0700 Message-ID: <000000000000da8a9b0570a29c01@google.com> Subject: INFO: task hung in iterate_supers From: syzbot To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Hello, syzbot found the following crash on: HEAD commit: d00d6d9a339d Add linux-next specific files for 20180709 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=111179b2400000 kernel config: https://syzkaller.appspot.com/x/.config?x=94fe2b586beccacd dashboard link: https://syzkaller.appspot.com/bug?extid=2349f5067b1772c1d8a5 compiler: gcc (GCC) 8.0.1 20180413 (experimental) syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=174329b2400000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11229044400000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+2349f5067b1772c1d8a5@syzkaller.appspotmail.com INFO: task syz-executor687:4459 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor687 D23544 4459 4456 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xc3/0x1d0 kernel/locking/rwsem.c:26 iterate_supers+0xe2/0x290 fs/super.c:728 ksys_sync+0xec/0x1e0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4498c9 Code: e8 1c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab d2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0ad5912da8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00000000006dac44 RCX: 00000000004498c9 RDX: 00000000004498c9 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000006dac40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0030656c69662f2e R13: 3d6e6f6973726576 R14: 64663d736e617274 R15: 0000000000000001 INFO: task syz-executor687:4479 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor687 D25408 4479 4456 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xc3/0x1d0 kernel/locking/rwsem.c:26 iterate_supers+0xe2/0x290 fs/super.c:728 ksys_sync+0x10c/0x1e0 fs/sync.c:115 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4498c9 Code: e8 1c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab d2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0ad58f1da8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00000000006dac5c RCX: 00000000004498c9 RDX: 00000000004498c9 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000006dac58 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0030656c69662f2e R13: 3d6e6f6973726576 R14: 64663d736e617274 R15: 0000000000000001 INFO: task syz-executor687:4492 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor687 D22992 4492 4456 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xc3/0x1d0 kernel/locking/rwsem.c:26 iterate_supers+0xe2/0x290 fs/super.c:728 ksys_sync+0xec/0x1e0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4498c9 Code: e8 1c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab d2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0ad58d0da8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00000000006dac74 RCX: 00000000004498c9 RDX: 00000000004498c9 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000006dac70 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0030656c69662f2e R13: 3d6e6f6973726576 R14: 64663d736e617274 R15: 0000000000000001 INFO: task syz-executor687:4497 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor687 D25408 4497 4456 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xc3/0x1d0 kernel/locking/rwsem.c:26 iterate_supers+0xe2/0x290 fs/super.c:728 ksys_sync+0xec/0x1e0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4498c9 Code: e8 1c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab d2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0ad58afda8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00000000006dac8c RCX: 00000000004498c9 RDX: 00000000004498c9 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000006dac88 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0030656c69662f2e R13: 3d6e6f6973726576 R14: 64663d736e617274 R15: 0000000000000001 INFO: task syz-executor687:4503 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor687 D24512 4503 4456 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xc3/0x1d0 kernel/locking/rwsem.c:26 iterate_supers+0xe2/0x290 fs/super.c:728 ksys_sync+0xec/0x1e0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4498c9 Code: e8 1c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab d2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0ad588eda8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00000000006daca4 RCX: 00000000004498c9 RDX: 00000000004498c9 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000006daca0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0030656c69662f2e R13: 3d6e6f6973726576 R14: 64663d736e617274 R15: 0000000000000001 INFO: task syz-executor687:4521 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor687 D23648 4521 4456 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xc3/0x1d0 kernel/locking/rwsem.c:26 iterate_supers+0xe2/0x290 fs/super.c:728 ksys_sync+0xec/0x1e0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4498c9 Code: e8 1c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab d2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0ad586dda8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00000000006dacbc RCX: 00000000004498c9 RDX: 00000000004498c9 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000006dacb8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0030656c69662f2e R13: 3d6e6f6973726576 R14: 64663d736e617274 R15: 0000000000000001 INFO: task syz-executor687:4524 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor687 D23640 4524 4456 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xc3/0x1d0 kernel/locking/rwsem.c:26 iterate_supers+0xe2/0x290 fs/super.c:728 ksys_sync+0xec/0x1e0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4498c9 Code: e8 1c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab d2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0ad584cda8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00000000006dacd4 RCX: 00000000004498c9 RDX: 00000000004498c9 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000006dacd0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0030656c69662f2e R13: 3d6e6f6973726576 R14: 64663d736e617274 R15: 0000000000000001 INFO: task syz-executor687:4534 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor687 D23864 4534 4456 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xc3/0x1d0 kernel/locking/rwsem.c:26 iterate_supers+0xe2/0x290 fs/super.c:728 ksys_sync+0xec/0x1e0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4498c9 Code: e8 1c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab d2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0ad582bda8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00000000006dacec RCX: 00000000004498c9 RDX: 00000000004498c9 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000006dace8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0030656c69662f2e R13: 3d6e6f6973726576 R14: 64663d736e617274 R15: 0000000000000001 INFO: task syz-executor687:4548 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor687 D25408 4548 4456 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xc3/0x1d0 kernel/locking/rwsem.c:26 iterate_supers+0xe2/0x290 fs/super.c:728 ksys_sync+0xec/0x1e0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4498c9 Code: e8 1c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab d2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0ad580ada8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00000000006dad04 RCX: 00000000004498c9 RDX: 00000000004498c9 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000006dad00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0030656c69662f2e R13: 3d6e6f6973726576 R14: 64663d736e617274 R15: 0000000000000001 INFO: task syz-executor687:4556 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180709+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor687 D24480 4556 4456 0x00000000 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xc3/0x1d0 kernel/locking/rwsem.c:26 iterate_supers+0xe2/0x290 fs/super.c:728 ksys_sync+0xec/0x1e0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4498c9 Code: e8 1c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab d2 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0ad57e9da8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00000000006dad1c RCX: 00000000004498c9 RDX: 00000000004498c9 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000006dad18 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0030656c69662f2e R13: 3d6e6f6973726576 R14: 64663d736e617274 R15: 0000000000000001 INFO: lockdep is turned off. NMI backtrace for cpu 0 CPU: 0 PID: 899 Comm: khungtaskd Not tainted 4.18.0-rc3-next-20180709+ #2 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+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.5+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:143 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb39/0x10b0 kernel/hung_task.c:265 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 --- This bug 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@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with syzbot. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches