INFO: task syz-executor.2:22451 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:syz-executor.2 state:D stack:27784 pid:22451 ppid: 21864 flags:0x00004004 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 loop_remove+0x39/0xf0 drivers/block/loop.c:2080 loop_control_remove drivers/block/loop.c:2137 [inline] loop_control_ioctl+0x445/0x4a0 drivers/block/loop.c:2175 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: 0033:0x7fa23e0baae9 RSP: 002b:00007fa23b5ee188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa23e1ce0e0 RCX: 00007fa23e0baae9 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000005 RBP: 00007fa23e114f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc7d58896f R14: 00007fa23b5ee300 R15: 0000000000022000 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 3 locks held by kworker/u4:2/49: #0: ffff8880b9c39a98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:478 #1: ffff8880b9c279c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x173/0x490 kernel/sched/psi.c:871 #2: ffffffff8bb83ae0 (rcu_read_lock){....}-{1:2}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:410 [inline] #2: ffffffff8bb83ae0 (rcu_read_lock){....}-{1:2}, at: batadv_nc_worker+0xf3/0xfa0 net/batman-adv/network-coding.c:723 5 locks held by kworker/u4:4/982: 1 lock held by in:imklog/6218: #0: ffff888079fe2d70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 ============================================= 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: 2965 Comm: systemd-journal 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_preemption_disabled+0x3a/0x170 lib/smp_processor_id.c:56 Code: 44 00 00 65 44 8b 25 7d dc af 76 65 8b 1d ee 36 b0 76 81 e3 ff ff ff 7f 31 ff 89 de 0f 1f 44 00 00 85 db 74 11 0f 1f 44 00 00 <44> 89 e0 5b 5d 41 5c 41 5d 41 5e c3 0f 1f 44 00 00 9c 5b 81 e3 00 RSP: 0018:ffffc900027dfc88 EFLAGS: 00000002 RAX: ffffffffffffffff RBX: 0000000000000001 RCX: 1ffffffff1b228f9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffffff8a051760 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817e2bc8 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff89ac0c00 R14: ffff88807ecacb00 R15: 0000000000040560 FS: 00007f18302318c0(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f182db06000 CR3: 000000001b4c7000 CR4: 0000000000350ef0 Call Trace: lockdep_hardirqs_on+0x79/0x100 kernel/locking/lockdep.c:4354 ___slab_alloc+0xc41/0xfe0 mm/slub.c:2978 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109 slab_alloc_node mm/slub.c:3200 [inline] slab_alloc mm/slub.c:3242 [inline] kmem_cache_alloc+0x35c/0x3a0 mm/slub.c:3247 prepare_creds+0x3f/0x7b0 kernel/cred.c:260 access_override_creds fs/open.c:351 [inline] do_faccessat+0x3f4/0x850 fs/open.c:415 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: 0033:0x7f182f4ec9c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe9e255c28 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffe9e258b40 RCX: 00007f182f4ec9c7 RDX: 00007f182ff5da00 RSI: 0000000000000000 RDI: 0000562d3ab229a3 RBP: 00007ffe9e255c60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffe9e258b40 R15: 00007ffe9e256150 ---------------- Code disassembly (best guess): 0: 44 00 00 add %r8b,(%rax) 3: 65 44 8b 25 7d dc af mov %gs:0x76afdc7d(%rip),%r12d # 0x76afdc88 a: 76 b: 65 8b 1d ee 36 b0 76 mov %gs:0x76b036ee(%rip),%ebx # 0x76b03700 12: 81 e3 ff ff ff 7f and $0x7fffffff,%ebx 18: 31 ff xor %edi,%edi 1a: 89 de mov %ebx,%esi 1c: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 21: 85 db test %ebx,%ebx 23: 74 11 je 0x36 25: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) * 2a: 44 89 e0 mov %r12d,%eax <-- trapping instruction 2d: 5b pop %rbx 2e: 5d pop %rbp 2f: 41 5c pop %r12 31: 41 5d pop %r13 33: 41 5e pop %r14 35: c3 retq 36: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 3b: 9c pushfq 3c: 5b pop %rbx 3d: 81 .byte 0x81 3e: e3 00 jrcxz 0x40