R13: 00007ffecb8c208f R14: 00007f125bab8300 R15: 0000000000022000 ---[ end trace a32e41e40fb042e5 ]--- kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8450 Comm: syz-executor.5 Tainted: G W 5.4.161-syzkaller-00052-g57f9b292a6a3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:strlen+0x27/0x60 lib/string.c:551 Code: 0f 1f 00 41 57 41 56 53 49 89 fe 49 bf 00 00 00 00 00 fc ff df 48 89 f8 66 66 2e 0f 1f 84 00 00 00 00 00 48 89 c3 48 c1 e8 03 <42> 0f b6 04 38 84 c0 75 0b 48 8d 43 01 80 3b 00 75 e7 eb 13 89 d9 RSP: 0018:ffff8881ea94fcd0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: ffffc90000f4b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff81b18f1b R09: ffffed103d529fa0 R10: ffffed103d529fa0 R11: 0000000000000000 R12: ffff8881f18e44b0 R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000 FS: 00007f125bab8700(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001ead5e000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kernfs_name_hash fs/kernfs/dir.c:302 [inline] kernfs_find_ns+0x83/0x430 fs/kernfs/dir.c:847 kernfs_remove_by_name_ns+0x32/0x90 fs/kernfs/dir.c:1510 del_gendisk+0x93d/0xb70 block/genhd.c:833 loop_remove drivers/block/loop.c:2189 [inline] loop_control_ioctl+0x563/0x680 drivers/block/loop.c:2288 do_vfs_ioctl+0x6fb/0x15b0 fs/ioctl.c:47 ksys_ioctl fs/ioctl.c:742 [inline] __do_sys_ioctl fs/ioctl.c:749 [inline] __se_sys_ioctl fs/ioctl.c:747 [inline] __x64_sys_ioctl+0xd4/0x110 fs/ioctl.c:747 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f125c942059 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f125bab8168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f125ca54f60 RCX: 00007f125c942059 RDX: 000000000000000b RSI: 0000000000004c81 RDI: 0000000000000004 RBP: 00007f125c99c08d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffecb8c208f R14: 00007f125bab8300 R15: 0000000000022000 Modules linked in: ---[ end trace a32e41e40fb042e6 ]--- RIP: 0010:strlen+0x27/0x60 lib/string.c:551 Code: 0f 1f 00 41 57 41 56 53 49 89 fe 49 bf 00 00 00 00 00 fc ff df 48 89 f8 66 66 2e 0f 1f 84 00 00 00 00 00 48 89 c3 48 c1 e8 03 <42> 0f b6 04 38 84 c0 75 0b 48 8d 43 01 80 3b 00 75 e7 eb 13 89 d9 RSP: 0018:ffff8881ea94fcd0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: ffffc90000f4b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff81b18f1b R09: ffffed103d529fa0 R10: ffffed103d529fa0 R11: 0000000000000000 R12: ffff8881f18e44b0 R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000 FS: 00007f125bab8700(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001ead5e000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 0f 1f 00 nopl (%rax) 3: 41 57 push %r15 5: 41 56 push %r14 7: 53 push %rbx 8: 49 89 fe mov %rdi,%r14 b: 49 bf 00 00 00 00 00 movabs $0xdffffc0000000000,%r15 12: fc ff df 15: 48 89 f8 mov %rdi,%rax 18: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 1f: 00 00 00 00 23: 48 89 c3 mov %rax,%rbx 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 75 0b jne 0x3e 33: 48 8d 43 01 lea 0x1(%rbx),%rax 37: 80 3b 00 cmpb $0x0,(%rbx) 3a: 75 e7 jne 0x23 3c: eb 13 jmp 0x51 3e: 89 d9 mov %ebx,%ecx