RSP: 002b:00007f4b4b076028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f4b4a425fa0 RCX: 00007f4b4a19e199
RDX: 00000000000001ff RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f4b4a2358e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4b4a426038 R14: 00007f4b4a425fa0 R15: 00007ffd1d764228
 </TASK>
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000021: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f]
CPU: 0 UID: 0 PID: 313 Comm: syz.0.1 Not tainted syzkaller #0 5fe152ef41c0f52d2b9838e2edd0515112f50e23
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:cgroup_mkdir+0x122a/0x1600 kernel/cgroup/cgroup.c:5931
Code: eb 05 e8 79 4d 08 00 48 89 df e8 11 9e 00 00 48 81 fb 01 f0 ff ff 0f 83 9a fb ff ff 4c 8d b3 08 01 00 00 4d 89 f4 49 c1 ec 03 <43> 80 3c 2c 00 74 08 4c 89 f7 e8 f7 34 61 00 48 8b bb 08 01 00 00
RSP: 0018:ffffc9000b74fc88 EFLAGS: 00010206
RAX: 6716881dcc9c1700 RBX: 0000000000000000 RCX: ffff8881f6e3acc0
RDX: ffff88810efc9300 RSI: ffff88810ef3f000 RDI: ffff888100042000
RBP: ffffc9000b74fd38 R08: ffffffff81dc1158 R09: ffffffff81e02e3f
R10: ffffffff81e05924 R11: ffffffff81e0295e R12: 0000000000000021
R13: dffffc0000000000 R14: 0000000000000108 R15: ffff88810ef3f010
FS:  00007f4b4b0766c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558a436918 CR3: 000000010eb16000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 kernfs_iop_mkdir+0x1bb/0x2d0 fs/kernfs/dir.c:1250
 vfs_mkdir+0x58e/0x810 fs/namei.c:4265
 do_mkdirat+0x240/0x530 fs/namei.c:4288
 __do_sys_mkdirat fs/namei.c:4303 [inline]
 __se_sys_mkdirat fs/namei.c:4301 [inline]
 __x64_sys_mkdirat+0x8b/0xa0 fs/namei.c:4301
 x64_sys_call+0x2ba8/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:259
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f4b4a19e199
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4b4b076028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f4b4a425fa0 RCX: 00007f4b4a19e199
RDX: 00000000000001ff RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f4b4a2358e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4b4a426038 R14: 00007f4b4a425fa0 R15: 00007ffd1d764228
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:cgroup_mkdir+0x122a/0x1600 kernel/cgroup/cgroup.c:5931
Code: eb 05 e8 79 4d 08 00 48 89 df e8 11 9e 00 00 48 81 fb 01 f0 ff ff 0f 83 9a fb ff ff 4c 8d b3 08 01 00 00 4d 89 f4 49 c1 ec 03 <43> 80 3c 2c 00 74 08 4c 89 f7 e8 f7 34 61 00 48 8b bb 08 01 00 00
RSP: 0018:ffffc9000b74fc88 EFLAGS: 00010206
RAX: 6716881dcc9c1700 RBX: 0000000000000000 RCX: ffff8881f6e3acc0
RDX: ffff88810efc9300 RSI: ffff88810ef3f000 RDI: ffff888100042000
RBP: ffffc9000b74fd38 R08: ffffffff81dc1158 R09: ffffffff81e02e3f
R10: ffffffff81e05924 R11: ffffffff81e0295e R12: 0000000000000021
R13: dffffc0000000000 R14: 0000000000000108 R15: ffff88810ef3f010
FS:  00007f4b4b0766c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4b4a1eb880 CR3: 000000010eb16000 CR4: 00000000003526b0
----------------
Code disassembly (best guess):
   0:	eb 05                	jmp    0x7
   2:	e8 79 4d 08 00       	call   0x84d80
   7:	48 89 df             	mov    %rbx,%rdi
   a:	e8 11 9e 00 00       	call   0x9e20
   f:	48 81 fb 01 f0 ff ff 	cmp    $0xfffffffffffff001,%rbx
  16:	0f 83 9a fb ff ff    	jae    0xfffffbb6
  1c:	4c 8d b3 08 01 00 00 	lea    0x108(%rbx),%r14
  23:	4d 89 f4             	mov    %r14,%r12
  26:	49 c1 ec 03          	shr    $0x3,%r12
* 2a:	43 80 3c 2c 00       	cmpb   $0x0,(%r12,%r13,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 f7             	mov    %r14,%rdi
  34:	e8 f7 34 61 00       	call   0x613530
  39:	48 8b bb 08 01 00 00 	mov    0x108(%rbx),%rdi