INFO: task syz-executor.4:18494 blocked for more than 143 seconds. Not tainted 5.15.0-next-20211115-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:28152 pid:18494 ppid: 11432 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4987 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6268 schedule+0xd2/0x260 kernel/sched/core.c:6341 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178 lo_release+0x160/0x1f0 drivers/block/loop.c:1768 blkdev_put_whole block/bdev.c:694 [inline] blkdev_put+0x2fb/0x9e0 block/bdev.c:956 blkdev_close+0x6a/0x80 block/fops.c:515 __fput+0x286/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/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: 0033:0x7f88fa9f972b RSP: 002b:00007fff86d8c630 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007f88fa9f972b RDX: 0000001b2e326eac RSI: ffffffff83d669c5 RDI: 0000000000000004 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000001b2e32001c R10: 00000000000010cf R11: 0000000000000293 R12: 00007f88fab5ab60 R13: 00007f88fab5ab60 R14: 00007f88fab59f60 R15: 00000000000722f0 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83aa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by systemd-udevd/2972: #0: ffff88801a6d7118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb50 block/bdev.c:819 1 lock held by in:imklog/6223: #0: ffff88801e5c7c70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 3 locks held by kworker/u4:7/9989: #0: ffff8880b9d39a98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:478 #1: ffff888020bd26e0 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xab/0x15a0 kernel/sched/core.c:4003 #2: ffffffff8bb83aa0 (rcu_read_lock){....}-{1:2}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:410 [inline] #2: ffffffff8bb83aa0 (rcu_read_lock){....}-{1:2}, at: batadv_nc_worker+0xf3/0xfa0 net/batman-adv/network-coding.c:723 1 lock held by systemd-udevd/18120: #0: ffff88801a6d7118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb50 block/bdev.c:819 2 locks held by syz-executor.4/18494: #0: ffff88801a6d7118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x97/0x9e0 block/bdev.c:914 #1: ffff88801a6d2b60 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:1748 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-next-20211115-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:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 7934 Comm: kworker/u4:5 Not tainted 5.15.0-next-20211115-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_region_inline mm/kasan/generic.c:170 [inline] RIP: 0010:kasan_check_range+0x12c/0x180 mm/kasan/generic.c:189 Code: 00 74 ef 49 8d 04 2c 48 85 d2 75 0b 48 89 da 48 29 c2 e9 55 ff ff ff 49 39 d2 75 17 49 0f be 02 41 83 e1 07 49 39 c1 7d 0a 5b 01 00 00 00 5d 41 5c c3 44 89 c2 e8 53 ef ff ff 5b 83 f0 01 5d RSP: 0018:ffffc9000291fa48 EFLAGS: 00000046 RAX: fffffbfff1fee741 RBX: ffffffff8bb83aa0 RCX: ffffffff815ca136 RDX: fffffbfff1fee741 RSI: 0000000000000008 RDI: ffffffff8ff73a00 RBP: fffffbfff1fee740 R08: 0000000000000000 R09: ffffffff8ff73a07 R10: fffffbfff1fee740 R11: 0000000000000000 R12: ffff88802815a7f8 R13: ffff888028159d40 R14: 0000000000020000 R15: 0000000000020029 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f599b798018 CR3: 000000000b88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] hlock_class kernel/locking/lockdep.c:199 [inline] check_wait_context kernel/locking/lockdep.c:4700 [inline] __lock_acquire+0x3e6/0x54a0 kernel/locking/lockdep.c:4977 lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 rcu_lock_acquire include/linux/rcupdate.h:268 [inline] rcu_read_lock include/linux/rcupdate.h:688 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x12d/0xfa0 net/batman-adv/network-coding.c:723 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 00 74 ef 49 add %dh,0x49(%rdi,%rbp,8) 4: 8d 04 2c lea (%rsp,%rbp,1),%eax 7: 48 85 d2 test %rdx,%rdx a: 75 0b jne 0x17 c: 48 89 da mov %rbx,%rdx f: 48 29 c2 sub %rax,%rdx 12: e9 55 ff ff ff jmpq 0xffffff6c 17: 49 39 d2 cmp %rdx,%r10 1a: 75 17 jne 0x33 1c: 49 0f be 02 movsbq (%r10),%rax 20: 41 83 e1 07 and $0x7,%r9d 24: 49 39 c1 cmp %rax,%r9 27: 7d 0a jge 0x33 29: 5b pop %rbx * 2a: b8 01 00 00 00 mov $0x1,%eax <-- trapping instruction 2f: 5d pop %rbp 30: 41 5c pop %r12 32: c3 retq 33: 44 89 c2 mov %r8d,%edx 36: e8 53 ef ff ff callq 0xffffef8e 3b: 5b pop %rbx 3c: 83 f0 01 xor $0x1,%eax 3f: 5d pop %rbp