SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 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 Modules linked in: CPU: 0 PID: 13222 Comm: syz-executor.0 Not tainted 4.14.298-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 task: ffff88807c5a8680 task.stack: ffff88808c850000 RIP: 0010:sysfs_do_create_link_sd+0x56/0x120 fs/sysfs/symlink.c:35 RSP: 0018:ffff88808c857b48 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000010 RCX: 0000000000001c55 RDX: 0000000000000008 RSI: 0000000000000001 RDI: 0000000000000040 RBP: ffffffff87cbd4e0 R08: ffffffff8b9adda8 R09: 00000000000400ca R10: ffff88807c5a8f30 R11: ffff88807c5a8680 R12: ffff8880aee3e540 R13: ffffffff87cbd4e0 R14: 0000000000000001 R15: ffff8880852b725c FS: 00007fe984bd9700(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055659fcaf848 CR3: 00000000a3a0b000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: sysfs_do_create_link fs/sysfs/symlink.c:80 [inline] sysfs_create_link+0x5f/0xc0 fs/sysfs/symlink.c:92 device_add_disk+0x9f8/0xdc0 block/genhd.c:691 add_disk include/linux/genhd.h:396 [inline] loop_add+0x615/0x830 drivers/block/loop.c:1909 loop_control_ioctl+0x11a/0x3f0 drivers/block/loop.c:2006 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 Code: 84 a1 00 00 00 e8 eb 4e b1 ff 48 c7 c7 c0 d8 04 89 e8 9f af 80 05 48 8d 7b 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 a7 00 00 00 4c 8b 6b 30 4d 85 ed 74 4f e8 b2 RIP: sysfs_do_create_link_sd+0x56/0x120 fs/sysfs/symlink.c:35 RSP: ffff88808c857b48 ---[ end trace 225e8a318815e0de ]--- ---------------- Code disassembly (best guess): 0: 84 a1 00 00 00 e8 test %ah,-0x18000000(%rcx) 6: eb 4e jmp 0x56 8: b1 ff mov $0xff,%cl a: 48 c7 c7 c0 d8 04 89 mov $0xffffffff8904d8c0,%rdi 11: e8 9f af 80 05 callq 0x580afb5 16: 48 8d 7b 30 lea 0x30(%rbx),%rdi 1a: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 21: fc ff df 24: 48 89 fa mov %rdi,%rdx 27: 48 c1 ea 03 shr $0x3,%rdx * 2b: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2f: 0f 85 a7 00 00 00 jne 0xdc 35: 4c 8b 6b 30 mov 0x30(%rbx),%r13 39: 4d 85 ed test %r13,%r13 3c: 74 4f je 0x8d 3e: e8 .byte 0xe8 3f: b2 .byte 0xb2