INFO: task kworker/u4:3:89 blocked for more than 143 seconds. Not tainted 5.16.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:3 state:D stack:24912 pid: 89 ppid: 2 flags:0x00004000 Workqueue: nbd-del nbd_dev_remove_work Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178 del_gendisk+0x598/0x860 block/genhd.c:623 nbd_dev_remove+0x3c/0xf0 drivers/block/nbd.c:252 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 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83ae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 2 locks held by kworker/u4:3/89: #0: ffff88801a34b938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88801a34b938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88801a34b938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff88801a34b938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff88801a34b938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff88801a34b938 ((wq_completion)nbd-del){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc90001a8fdb0 ((work_completion)(&nbd->remove_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 1 lock held by systemd-udevd/2972: 1 lock held by in:imklog/6216: #0: ffff88801e101c70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 1 lock held by syz-executor.0/6549: #0: ffffffff8bb8ce68 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #0: ffffffff8bb8ce68 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4fa/0x620 kernel/rcu/tree_exp.h:836 1 lock held by syz-executor.4/22159: #0: ffffffff8bb8ce68 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #0: ffffffff8bb8ce68 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d5/0x620 kernel/rcu/tree_exp.h:836 2 locks held by kworker/1:12/24490: #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff888010c66538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc9000492fdb0 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 1 lock held by syz-executor.1/25019: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc1-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:210 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:295 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: 25020 Comm: syz-executor.3 Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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:ffffc9000aa47638 EFLAGS: 00000246 RAX: fffff940001a0fa7 RBX: ffff88802f5c86a8 RCX: ffffffff81a11a60 RDX: fffff940001a0fa7 RSI: 0000000000000004 RDI: ffffea0000d07d34 RBP: fffff940001a0fa6 R08: 0000000000000001 R09: ffffea0000d07d37 R10: fffff940001a0fa6 R11: 0000000000000000 R12: ffffea0000d07d34 R13: 00000000000000d3 R14: ffffea0000d07d00 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa518aaa564 CR3: 0000000035bc5000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:101 [inline] atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:542 [inline] page_ref_dec_and_test include/linux/page_ref.h:210 [inline] put_page_testzero include/linux/mm.h:738 [inline] release_pages+0x4a0/0x1480 mm/swap.c:947 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:242 [inline] tlb_flush_mmu+0xe9/0x6b0 mm/mmu_gather.c:249 zap_pte_range mm/memory.c:1418 [inline] zap_pmd_range mm/memory.c:1467 [inline] zap_pud_range mm/memory.c:1496 [inline] zap_p4d_range mm/memory.c:1517 [inline] unmap_page_range+0x1cac/0x29f0 mm/memory.c:1538 unmap_single_vma+0x198/0x310 mm/memory.c:1583 unmap_vmas+0x16b/0x2f0 mm/memory.c:1615 exit_mmap+0x1d0/0x630 mm/mmap.c:3170 __mmput+0x122/0x4b0 kernel/fork.c:1113 mmput+0x56/0x60 kernel/fork.c:1134 exit_mm kernel/exit.c:507 [inline] do_exit+0xb27/0x2b40 kernel/exit.c:819 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: 0033:0x7fa3d094dae9 Code: Unable to access opcode bytes at RIP 0x7fa3d094dabf. RSP: 002b:00007fa3cdea2218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fa3d0a61028 RCX: 00007fa3d094dae9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa3d0a61028 RBP: 00007fa3d0a61020 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa3d0a6102c R13: 00007ffd74a9b24f R14: 00007fa3cdea2300 R15: 0000000000022000 ---------------- 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