RSP: 002b:00007f482fcc2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f482fe5ef60 RCX: 00007f482fd4c109 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 RBP: 00007f482fda608d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc32454e5f R14: 00007f482fcc2300 R15: 0000000000022000 ---[ end trace d302474f4529ceb4 ]--- general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 421 Comm: syz-executor.0 Tainted: G W 5.10.43-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:strlen+0x1f/0xa0 lib/string.c:568 Code: 48 8b 45 e8 eb 88 0f 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 fa 48 89 e5 48 c1 ea 03 41 54 49 89 fc 53 48 83 ec 08 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 4d 41 80 3c 24 RSP: 0018:ffffc90000907c90 EFLAGS: 00010286 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff84262aa9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000907ca8 R08: 0000000000000001 R09: ffffc90000907cbf R10: fffff52000120f97 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000008 FS: 00007f482fcc2700(0000) GS:ffff8881f7200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f482fe5f028 CR3: 000000010d6e7000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kernfs_name_hash+0x16/0xc0 fs/kernfs/dir.c:302 kernfs_find_ns+0x84/0x210 fs/kernfs/dir.c:841 kernfs_remove_by_name_ns+0x32/0x80 fs/kernfs/dir.c:1514 kernfs_remove_by_name include/linux/kernfs.h:608 [inline] sysfs_remove_link+0x37/0xa0 fs/sysfs/symlink.c:152 del_gendisk+0x5f8/0xa60 block/genhd.c:951 loop_remove drivers/block/loop.c:2194 [inline] loop_control_ioctl drivers/block/loop.c:2293 [inline] loop_control_ioctl+0x30d/0x3d0 drivers/block/loop.c:2259 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x129/0x1a0 fs/ioctl.c:739 do_syscall_64+0x32/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f482fd4c109 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:00007f482fcc2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f482fe5ef60 RCX: 00007f482fd4c109 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 RBP: 00007f482fda608d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc32454e5f R14: 00007f482fcc2300 R15: 0000000000022000 Modules linked in: ---[ end trace d302474f4529ceb5 ]--- RIP: 0010:strlen+0x1f/0xa0 lib/string.c:568 Code: 48 8b 45 e8 eb 88 0f 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 fa 48 89 e5 48 c1 ea 03 41 54 49 89 fc 53 48 83 ec 08 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 4d 41 80 3c 24 RSP: 0018:ffffc90000907c90 EFLAGS: 00010286 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff84262aa9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000907ca8 R08: 0000000000000001 R09: ffffc90000907cbf R10: fffff52000120f97 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000008 FS: 00007f482fcc2700(0000) GS:ffff8881f7200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f482fe5f028 CR3: 000000010d6e7000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 48 8b 45 e8 mov -0x18(%rbp),%rax 4: eb 88 jmp 0xffffff8e 6: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) b: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 12: fc ff df 15: 55 push %rbp 16: 48 89 fa mov %rdi,%rdx 19: 48 89 e5 mov %rsp,%rbp 1c: 48 c1 ea 03 shr $0x3,%rdx 20: 41 54 push %r12 22: 49 89 fc mov %rdi,%r12 25: 53 push %rbx 26: 48 83 ec 08 sub $0x8,%rsp * 2a: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction 2e: 48 89 fa mov %rdi,%rdx 31: 83 e2 07 and $0x7,%edx 34: 38 d0 cmp %dl,%al 36: 7f 04 jg 0x3c 38: 84 c0 test %al,%al 3a: 75 4d jne 0x89 3c: 41 rex.B 3d: 80 .byte 0x80 3e: 3c 24 cmp $0x24,%al