INFO: task syz-executor.1:31362 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.1 state:D stack:28968 pid:31362 ppid: 10129 flags:0x20004004 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 __loop_clr_fd+0x1ae/0x1070 drivers/block/loop.c:1122 loop_clr_fd drivers/block/loop.c:1237 [inline] lo_ioctl+0x398/0x17c0 drivers/block/loop.c:1562 lo_compat_ioctl+0xb1/0x110 drivers/block/loop.c:1718 compat_blkdev_ioctl+0x3b8/0x810 block/ioctl.c:674 __do_compat_sys_ioctl+0x1c7/0x290 fs/ioctl.c:972 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf6ec6549 RSP: 002b:00000000f445d5fc EFLAGS: 00000296 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000004c01 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 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 1 lock held by in:imklog/6447: #0: ffff888075336370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by agetty/6454: #0: ffff88801ca7d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252 #1: ffffc9000296c2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113 1 lock held by syz-executor.1/31362: #0: ffff888019fbb360 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x7a/0x1070 drivers/block/loop.c:1106 2 locks held by systemd-udevd/31365: #0: ffff888019fbf918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb50 block/bdev.c:819 #1: ffff888019fbb360 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_open+0x75/0x120 drivers/block/loop.c:1733 ============================================= 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: 2951 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:on_stack arch/x86/include/asm/stacktrace.h:55 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:342 [inline] RIP: 0010:deref_stack_reg+0x4e/0x150 arch/x86/kernel/unwind_orc.c:352 Code: 0f b6 04 02 84 c0 74 08 3c 03 0f 8e d7 00 00 00 41 8b 04 24 85 c0 74 62 49 8d 7c 24 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa <48> c1 ea 03 80 3c 02 00 0f 85 c3 00 00 00 49 8d 7c 24 10 4d 8b 6c RSP: 0018:ffffc9000c02f8d8 EFLAGS: 00000202 RAX: dffffc0000000000 RBX: ffffc9000c02fa28 RCX: ffffffff8e1095a7 RDX: ffffc9000c02f9e8 RSI: ffffc9000c02fb00 RDI: ffffc9000c02f9e8 RBP: ffffc9000c02fb00 R08: ffffffff8e1095a2 R09: 0000000000000001 R10: fffff52001805f47 R11: 000000000008808a R12: ffffc9000c02f9e0 R13: ffffc9000c02fa15 R14: ffffc9000c02f9e0 R15: ffffffff8e1095a6 FS: 00007fec39a6f8c0(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fec370b4000 CR3: 000000001ce41000 CR4: 00000000003526f0 Call Trace: unwind_next_frame+0xcdc/0x1ce0 arch/x86/kernel/unwind_orc.c:534 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1749 slab_free mm/slub.c:3513 [inline] kmem_cache_free+0x92/0x5e0 mm/slub.c:3529 putname fs/namei.c:270 [inline] putname+0xfe/0x140 fs/namei.c:256 user_path_at_empty+0x4d/0x60 fs/namei.c:2803 user_path_at include/linux/namei.h:57 [inline] do_faccessat+0x127/0x850 fs/open.c:421 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: 0033:0x7fec38d2a9c7 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:00007fffd43cf308 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007fffd43d2330 RCX: 00007fec38d2a9c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000559e953309a3 RBP: 00007fffd43cf450 R08: 0000559e953263e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000559e960c18a0 R15: 00007fffd43cf940 ---------------- Code disassembly (best guess): 0: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax 4: 84 c0 test %al,%al 6: 74 08 je 0x10 8: 3c 03 cmp $0x3,%al a: 0f 8e d7 00 00 00 jle 0xe7 10: 41 8b 04 24 mov (%r12),%eax 14: 85 c0 test %eax,%eax 16: 74 62 je 0x7a 18: 49 8d 7c 24 08 lea 0x8(%r12),%rdi 1d: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 24: fc ff df 27: 48 89 fa mov %rdi,%rdx * 2a: 48 c1 ea 03 shr $0x3,%rdx <-- trapping instruction 2e: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 32: 0f 85 c3 00 00 00 jne 0xfb 38: 49 8d 7c 24 10 lea 0x10(%r12),%rdi 3d: 4d rex.WRB 3e: 8b .byte 0x8b 3f: 6c insb (%dx),%es:(%rdi)