Hello, When using Healer to fuzz the latest Linux kernel, the following crash was triggered. HEAD commit: ff1ffd71d5f0 Merge tag 'hyperv-fixes-signed-20210915 git tree: upstream console output: https://drive.google.com/file/d/1Htx96ZZ5dAxLIr-4jNJ62iQdstmHnliH/view?usp=sharing kernel config: https://drive.google.com/file/d/1zXpDhs-IdE7tX17B7MhaYP0VGUfP6m9B/view?usp=sharing Sorry, I don't have a reproducer for this crash, hope the symbolized report can help. If you fix this issue, please add the following tag to the commit: Reported-by: Hao Sun <sunhao.th@xxxxxxxxx> INFO: task syz-executor:25816 blocked for more than 143 seconds. Not tainted 5.15.0-rc1+ #6 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:27872 pid:25816 ppid: 24814 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xcd9/0x2530 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425 __mutex_lock_common kernel/locking/mutex.c:669 [inline] __mutex_lock+0xc96/0x1680 kernel/locking/mutex.c:729 nbd_ioctl+0x14f/0x9c0 drivers/block/nbd.c:1455 blkdev_ioctl+0x2a4/0x720 block/ioctl.c:589 block_ioctl+0xfa/0x140 block/fops.c:477 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 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: 0033:0x4739cd RSP: 002b:00007fe430645c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000059c0a0 RCX: 00000000004739cd RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000007 RBP: 00000000004ebd80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000059c0a0 R13: 00007ffcaa94abdf R14: 00007ffcaa94ad80 R15: 00007fe430645dc0 INFO: task syz-executor:25822 blocked for more than 143 seconds. Not tainted 5.15.0-rc1+ #6 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:28400 pid:25822 ppid: 24814 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xcd9/0x2530 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 blk_mq_freeze_queue_wait+0x114/0x160 block/blk-mq.c:151 nbd_add_socket+0x102/0x7c0 drivers/block/nbd.c:1050 __nbd_ioctl drivers/block/nbd.c:1405 [inline] nbd_ioctl+0x391/0x9c0 drivers/block/nbd.c:1462 blkdev_ioctl+0x2a4/0x720 block/ioctl.c:589 block_ioctl+0xfa/0x140 block/fops.c:477 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 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: 0033:0x4739cd RSP: 002b:00007fe430603c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000059c210 RCX: 00000000004739cd RDX: 0000000000000005 RSI: 000000000000ab00 RDI: 0000000000000004 RBP: 00000000004ebd80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000059c210 R13: 00007ffcaa94abdf R14: 00007ffcaa94ad80 R15: 00007fe430603dc0 INFO: task syz-executor:25823 blocked for more than 143 seconds. Not tainted 5.15.0-rc1+ #6 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:27408 pid:25823 ppid: 24814 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xcd9/0x2530 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 blk_queue_enter+0x956/0xdb0 block/blk-core.c:462 bio_queue_enter block/blk-core.c:477 [inline] __submit_bio_noacct_mq block/blk-core.c:989 [inline] submit_bio_noacct+0xd32/0x1460 block/blk-core.c:1031 submit_bio+0x10a/0x460 block/blk-core.c:1093 submit_bio_wait+0x106/0x230 block/bio.c:1248 blkdev_issue_flush+0xd7/0x120 block/blk-flush.c:458 blkdev_fsync+0x8e/0xd0 block/fops.c:420 vfs_fsync_range+0x13a/0x220 fs/sync.c:200 vfs_fsync fs/sync.c:214 [inline] do_fsync+0x4d/0x90 fs/sync.c:224 __do_sys_fsync fs/sync.c:232 [inline] __se_sys_fsync fs/sync.c:230 [inline] __x64_sys_fsync+0x2f/0x40 fs/sync.c:230 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: 0033:0x2000014c RSP: 002b:00007fe4305e2bb8 EFLAGS: 00000213 ORIG_RAX: 000000000000004a RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 000000002000014c RDX: 0000000000004c01 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 00000000000000b9 R08: 0000000000000005 R09: 0000000000000006 R10: 0000000000000007 R11: 0000000000000213 R12: 000000000000000b R13: 000000000000000c R14: 000000000000000d R15: 00007fe4305e2dc0 Showing all locks held in the system: 1 lock held by khungtaskd/39: #0: ffffffff8b97e9a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 1 lock held by in:imklog/6298: #0: ffff88801c9d19f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 3 locks held by kworker/u8:2/6743: 1 lock held by syz-executor/25816: #0: ffff88801ae63208 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x14f/0x9c0 drivers/block/nbd.c:1455 1 lock held by syz-executor/25822: #0: ffff88801ae63208 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x14f/0x9c0 drivers/block/nbd.c:1455 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 39 Comm: khungtaskd Not tainted 5.15.0-rc1+ #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 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+0x1e1/0x220 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xcc8/0x1010 kernel/hung_task.c:295 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0,2-3: NMI backtrace for cpu 0 CPU: 0 PID: 3022 Comm: systemd-journal Not tainted 5.15.0-rc1+ #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:__orc_find+0x0/0xf0 arch/x86/kernel/unwind_orc.c:35 Code: 7f 8b e8 63 a6 c8 02 e9 60 fb ff ff e8 b9 96 8a 00 e9 cf fb ff ff cc cc cc cc 48 8b 07 c3 66 66 2e 0f 1f 84 00 00 00 00 00 90 <41> 57 89 d0 41 56 41 55 41 54 4c 8d 64 87 fc 55 53 48 83 ec 10 85 RSP: 0018:ffffc9000121f980 EFLAGS: 00000212 RAX: 000000000002c858 RBX: 1ffff92000243f39 RCX: ffffffff81bdbadf RDX: 000000000000000b RSI: ffffffff8df4036c RDI: ffffffff8d82b228 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8df4036c R10: ffffc9000121fadf R11: 0000000000086088 R12: ffffc9000121fac8 R13: ffffc9000121fab5 R14: ffffc9000121fa80 R15: ffffffff81bdbadf FS: 00007f13812868c0(0000) GS:ffff888063e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f137ce35000 CR3: 0000000018bf1000 CR4: 0000000000350ef0 Call Trace: orc_find arch/x86/kernel/unwind_orc.c:173 [inline] unwind_next_frame+0x33a/0x1770 arch/x86/kernel/unwind_orc.c:443 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0x100/0x140 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1700 [inline] slab_free_freelist_hook mm/slub.c:1725 [inline] slab_free mm/slub.c:3483 [inline] kmem_cache_free+0xa0/0x670 mm/slub.c:3499 putname+0xfe/0x140 fs/namei.c:270 do_mkdirat+0x18a/0x2b0 fs/namei.c:3920 __do_sys_mkdir fs/namei.c:3931 [inline] __se_sys_mkdir fs/namei.c:3929 [inline] __x64_sys_mkdir+0x61/0x80 fs/namei.c:3929 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: 0033:0x7f1380542687 Code: 00 b8 ff ff ff ff c3 0f 1f 40 00 48 8b 05 09 d8 2b 00 64 c7 00 5f 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 b8 53 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 d7 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffcb3a1e5b8 EFLAGS: 00000293 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007ffcb3a214d0 RCX: 00007f1380542687 RDX: 00007f1380fb3a00 RSI: 00000000000001ed RDI: 00005567696f38a0 RBP: 00007ffcb3a1e5f0 R08: 000000000000c000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffcb3a214d0 R15: 00007ffcb3a1eae0 NMI backtrace for cpu 3 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 3 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 3 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:716 NMI backtrace for cpu 2 CPU: 2 PID: 6743 Comm: kworker/u8:2 Not tainted 5.15.0-rc1+ #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: netns cleanup_net RIP: 0010:check_wait_context kernel/locking/lockdep.c:4693 [inline] RIP: 0010:__lock_acquire+0x4b6/0x57e0 kernel/locking/lockdep.c:4965 Code: 06 49 81 c7 40 fd cf 8f 45 84 e4 0f 84 f8 02 00 00 48 8d 7d 21 48 b8 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 0f b6 04 01 <48> 89 f9 83 e1 07 38 c8 7f 08 84 c0 0f 85 62 33 00 00 44 0f b6 4d RSP: 0018:ffffc9000308f8f0 EFLAGS: 00000012 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 1ffff11005adb152 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88802d6d8a91 RBP: ffff88802d6d8a70 R08: 0000000000000001 R09: fffffbfff1f9ff25 R10: ffffffff8fcff927 R11: fffffbfff1f9ff24 R12: 0000000000000002 R13: ffff88802d6d8000 R14: ffffffff8b97e9a0 R15: ffffffff8fd00280 FS: 0000000000000000(0000) GS:ffff888063f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000002a6ac48 CR3: 000000000b68e000 CR4: 0000000000350ee0 Call Trace: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x520 kernel/locking/lockdep.c:5590 rcu_lock_acquire include/linux/rcupdate.h:267 [inline] rcu_read_lock include/linux/rcupdate.h:687 [inline] inet_twsk_purge+0x117/0x7b0 net/ipv4/inet_timewait_sock.c:268 ops_exit_list.isra.0+0x103/0x150 net/core/net_namespace.c:171 cleanup_net+0x511/0xa90 net/core/net_namespace.c:591 process_one_work+0x9df/0x16d0 kernel/workqueue.c:2297 worker_thread+0x90/0xed0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 7f 8b jg 0xffffff8d 2: e8 63 a6 c8 02 callq 0x2c8a66a 7: e9 60 fb ff ff jmpq 0xfffffb6c c: e8 b9 96 8a 00 callq 0x8a96ca 11: e9 cf fb ff ff jmpq 0xfffffbe5 16: cc int3 17: cc int3 18: cc int3 19: cc int3 1a: 48 8b 07 mov (%rdi),%rax 1d: c3 retq 1e: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 25: 00 00 00 00 29: 90 nop * 2a: 41 57 push %r15 <-- trapping instruction 2c: 89 d0 mov %edx,%eax 2e: 41 56 push %r14 30: 41 55 push %r13 32: 41 54 push %r12 34: 4c 8d 64 87 fc lea -0x4(%rdi,%rax,4),%r12 39: 55 push %rbp 3a: 53 push %rbx 3b: 48 83 ec 10 sub $0x10,%rsp 3f: 85 .byte 0x85
