INFO: task syz-executor.2:17888 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D29920 17888 8160 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 Dev loop0: unable to read RDB block 8 loop0: unable to read partition table schedule+0x8d/0x1b0 kernel/sched/core.c:3561 loop0: partition table beyond EOD, truncated __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x20a/0x390 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0x44/0x80 kernel/locking/rwsem.c:26 iterate_supers+0xdb/0x290 fs/super.c:631 ksys_sync+0x86/0x150 fs/sync.c:113 __ia32_sys_sync+0xa/0x10 fs/sync.c:124 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fa3164150c9 Code: Bad RIP value. RSP: 002b:00007fa314987168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fa316534f80 RCX: 00007fa3164150c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fa316470ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc1298e41f R14: 00007fa314987300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1570: #0: 0000000036540dee (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7813: #0: 00000000c4b402f9 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 3 locks held by kworker/u4:10/5834: 1 lock held by syz-executor.0/25803: #0: 000000008f6320ea (&type->s_umount_key#93/1){+.+.}, at: alloc_super fs/super.c:226 [inline] #0: 000000008f6320ea (&type->s_umount_key#93/1){+.+.}, at: sget_userns+0x20b/0xcd0 fs/super.c:519 1 lock held by syz-executor.2/17888: #0: 000000008f6320ea (&type->s_umount_key#96){.+.+}, at: iterate_supers+0xdb/0x290 fs/super.c:631 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4691 Comm: systemd-journal Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 RIP: 0010:strlen+0x58/0x90 lib/string.c:539 Code: 00 00 74 39 48 bb 00 00 00 00 00 fc ff df 48 89 e8 48 83 c0 01 48 89 c2 48 89 c1 48 c1 ea 03 83 e1 07 0f b6 14 1a 38 ca 7f 04 <84> d2 75 1f 80 38 00 75 de 48 83 c4 08 48 29 e8 5b 5d c3 48 83 c4 RSP: 0018:ffff8880a13ffbd0 EFLAGS: 00000093 RAX: ffffffff88b3ec6d RBX: dffffc0000000000 RCX: 0000000000000005 RDX: 0000000000000000 RSI: ffffffff8d40d520 RDI: ffffffff88b3ec60 RBP: ffffffff88b3ec60 R08: ffff8880a9d014d0 R09: ffff888039290f10 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89f6d360 R13: ffffffff8d40d520 R14: ffffffff814a7850 R15: ffff8880a13ffca0 FS: 00007fceb11c18c0(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fceae79d000 CR3: 00000000a12d2000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: strlen include/linux/string.h:299 [inline] trace_event_get_offsets_lock include/trace/events/lock.h:39 [inline] perf_trace_lock+0xb1/0x4b0 include/trace/events/lock.h:39 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x4e8/0x8b0 kernel/locking/lockdep.c:3926 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_unlock_irqrestore+0x1b/0xe0 kernel/locking/spinlock.c:184 __debug_check_no_obj_freed lib/debugobjects.c:798 [inline] debug_check_no_obj_freed+0x201/0x490 lib/debugobjects.c:817 kmem_cache_free+0xff/0x260 mm/slab.c:3764 __put_cred+0x1de/0x250 kernel/cred.c:151 put_cred include/linux/cred.h:279 [inline] do_faccessat+0x64e/0x7a0 fs/open.c:438 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fceb047c9c7 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:00007ffcb8f576a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffcb8f5a5c0 RCX: 00007fceb047c9c7 RDX: 00007fceb0eeda00 RSI: 0000000000000000 RDI: 000055a5784a39a3 RBP: 00007ffcb8f576e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffcb8f5a5c0 R15: 00007ffcb8f57bd0