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/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 ---[ end trace 8b0af1f7665720ad ]--- 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: 24672 Comm: syz-executor.3 Tainted: G W 5.4.219-syzkaller-00012-ga8aad8851131 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:kill_device drivers/base/core.c:3022 [inline] RIP: 0010:device_del+0xe7/0x1000 drivers/base/core.c:3049 Code: df e8 4d 6f 04 ff 4c 89 7c 24 18 41 bf c8 00 00 00 48 89 5c 24 08 4c 03 3b 4d 89 fc 49 c1 ec 03 48 b8 00 00 00 00 00 fc ff df <41> 8a 04 04 84 c0 0f 85 88 0e 00 00 41 0f b6 1f 89 de 83 e6 01 31 RSP: 0018:ffff8881ef54f9a0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8881e70e40d8 RCX: 1ffff1103ce1c81b RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8881ef54f920 RBP: ffff8881ef54fa70 R08: dffffc0000000000 R09: ffffed103dea9f25 R10: ffffed103dea9f25 R11: 1ffff1103dea9f24 R12: 0000000000000019 R13: ffff8881e70e4070 R14: ffff8881e70e4110 R15: 00000000000000c8 FS: 00007f1157c99700(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0200d9ddc0 CR3: 00000001e54e2000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: del_gendisk+0x99c/0xbf0 block/genhd.c:835 loop_remove+0x42/0xa0 drivers/block/loop.c:2194 loop_control_ioctl+0x67f/0x740 drivers/block/loop.c:2293 do_vfs_ioctl+0x744/0x1730 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/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Modules linked in: ---[ end trace 8b0af1f7665720ae ]--- RIP: 0010:kill_device drivers/base/core.c:3022 [inline] RIP: 0010:device_del+0xe7/0x1000 drivers/base/core.c:3049 Code: df e8 4d 6f 04 ff 4c 89 7c 24 18 41 bf c8 00 00 00 48 89 5c 24 08 4c 03 3b 4d 89 fc 49 c1 ec 03 48 b8 00 00 00 00 00 fc ff df <41> 8a 04 04 84 c0 0f 85 88 0e 00 00 41 0f b6 1f 89 de 83 e6 01 31 RSP: 0018:ffff8881ef54f9a0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8881e70e40d8 RCX: 1ffff1103ce1c81b RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8881ef54f920 RBP: ffff8881ef54fa70 R08: dffffc0000000000 R09: ffffed103dea9f25 R10: ffffed103dea9f25 R11: 1ffff1103dea9f24 R12: 0000000000000019 R13: ffff8881e70e4070 R14: ffff8881e70e4110 R15: 00000000000000c8 FS: 00007f1157c99700(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff40062a000 CR3: 00000001e54e2000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: df e8 fucomip %st(0),%st 2: 4d 6f rex.WRB outsl %ds:(%rsi),(%dx) 4: 04 ff add $0xff,%al 6: 4c 89 7c 24 18 mov %r15,0x18(%rsp) b: 41 bf c8 00 00 00 mov $0xc8,%r15d 11: 48 89 5c 24 08 mov %rbx,0x8(%rsp) 16: 4c 03 3b add (%rbx),%r15 19: 4d 89 fc mov %r15,%r12 1c: 49 c1 ec 03 shr $0x3,%r12 20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 27: fc ff df * 2a: 41 8a 04 04 mov (%r12,%rax,1),%al <-- trapping instruction 2e: 84 c0 test %al,%al 30: 0f 85 88 0e 00 00 jne 0xebe 36: 41 0f b6 1f movzbl (%r15),%ebx 3a: 89 de mov %ebx,%esi 3c: 83 e6 01 and $0x1,%esi 3f: 31 .byte 0x31