[v6.1] general protection fault in sysfs_move_dir_ns

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: ad16b162f21d Linux 6.1.172
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13109696580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0605c5af04d7603
dashboard link: https://syzkaller.appspot.com/bug?extid=f462cd7198b2f409facf
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2188b271cf45/disk-ad16b162.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/356336b9737c/vmlinux-ad16b162.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3453b10f11f7/bzImage-ad16b162.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f462cd...@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]
CPU: 0 PID: 16237 Comm: syz.3.3160 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:sysfs_move_dir_ns+0xa6/0xd0 fs/sysfs/dir.c:126
Code: 96 48 c1 e8 03 42 80 3c 20 00 74 0c 48 c7 c7 c0 61 d3 96 e8 7c 5a cb ff 4c 8b 3d a5 3a cb 14 49 8d 7e 38 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 5e 5a cb ff 49 8b 56 38 4c 89 f7 4c 89 fe
RSP: 0018:ffffc90004a778f8 EFLAGS: 00010202
RAX: 0000000000000007 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000f0f9000 RSI: 000000000000dcca RDI: 0000000000000038
RBP: ffffc90004a779d8 R08: ffff88801a3e5940 R09: 0000000000000012
R10: 0000000000000012 R11: 0000000000000002 R12: dffffc0000000000
R13: ffff888026bc0bc0 R14: 0000000000000000 R15: ffff88801cede3a0
FS: 00007f0c0822f6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0c073ea4c0 CR3: 00000000661d9000 CR4: 00000000003506f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000007
DR3: ffffffffefffff15 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
kobject_move+0x546/0x700 lib/kobject.c:561
device_move+0xdc/0x6f0 drivers/base/core.c:4624
hci_conn_del_sysfs+0xab/0x160 net/bluetooth/hci_sysfs.c:73
hci_conn_cleanup+0x575/0x730 net/bluetooth/hci_conn.c:172
hci_conn_del+0x515/0x720 net/bluetooth/hci_conn.c:1152
hci_conn_hash_flush+0x203/0x290 net/bluetooth/hci_conn.c:2511
hci_dev_close_sync+0x933/0xf40 net/bluetooth/hci_sync.c:5247
hci_dev_do_close net/bluetooth/hci_core.c:528 [inline]
hci_rfkill_set_block+0x127/0x1f0 net/bluetooth/hci_core.c:935
rfkill_set_block+0x1c9/0x3d0 net/rfkill/core.c:360
rfkill_fop_write+0x452/0x560 net/rfkill/core.c:1318
vfs_write+0x2e6/0xa30 fs/read_write.c:582
ksys_write+0x14c/0x250 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0c0739cdd9
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:00007f0c0822f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0c07615fa0 RCX: 00007f0c0739cdd9
RDX: 0000000000000008 RSI: 0000200000000080 RDI: 0000000000000003
RBP: 00007f0c07432d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c07616038 R14: 00007f0c07615fa0 R15: 00007fff397a33e8
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:sysfs_move_dir_ns+0xa6/0xd0 fs/sysfs/dir.c:126
Code: 96 48 c1 e8 03 42 80 3c 20 00 74 0c 48 c7 c7 c0 61 d3 96 e8 7c 5a cb ff 4c 8b 3d a5 3a cb 14 49 8d 7e 38 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 74 05 e8 5e 5a cb ff 49 8b 56 38 4c 89 f7 4c 89 fe
RSP: 0018:ffffc90004a778f8 EFLAGS: 00010202
RAX: 0000000000000007 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000f0f9000 RSI: 000000000000dcca RDI: 0000000000000038
RBP: ffffc90004a779d8 R08: ffff88801a3e5940 R09: 0000000000000012
R10: 0000000000000012 R11: 0000000000000002 R12: dffffc0000000000
R13: ffff888026bc0bc0 R14: 0000000000000000 R15: ffff88801cede3a0
FS: 00007f0c0822f6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f598a85fe9c CR3: 00000000661d9000 CR4: 00000000003506e0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000007
DR3: ffffffffefffff15 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 96 xchg %eax,%esi
1: 48 c1 e8 03 shr $0x3,%rax
5: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1)
a: 74 0c je 0x18
c: 48 c7 c7 c0 61 d3 96 mov $0xffffffff96d361c0,%rdi
13: e8 7c 5a cb ff call 0xffcb5a94
18: 4c 8b 3d a5 3a cb 14 mov 0x14cb3aa5(%rip),%r15 # 0x14cb3ac4
1f: 49 8d 7e 38 lea 0x38(%r14),%rdi
23: 48 89 f8 mov %rdi,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction
2f: 74 05 je 0x36
31: e8 5e 5a cb ff call 0xffcb5a94
36: 49 8b 56 38 mov 0x38(%r14),%rdx
3a: 4c 89 f7 mov %r14,%rdi
3d: 4c 89 fe mov %r15,%rsi


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