[v6.1] BUG: unable to handle kernel paging request in getname_kernel

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fb28aa725e05 Linux 6.1.180
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=144713b9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=872c04466179833f
dashboard link: https://syzkaller.appspot.com/bug?extid=f613f9f010ec98eb9d86
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d420eb944682/disk-fb28aa72.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/affae450ab23/vmlinux-fb28aa72.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b9e6919ed519/Image-fb28aa72.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f613f9...@syzkaller.appspotmail.com

nvmet: adding nsid 1 to subsystem testnqn
Unable to handle kernel paging request at virtual address dfff800000000000
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
Mem abort info:
ESR = 0x0000000096000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x06: level 2 translation fault
Data abort info:
ISV = 0, ISS = 0x00000006
CM = 0, WnR = 0
[dfff800000000000] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4422 Comm: syz.3.4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : strlen+0x28/0x84 lib/string.c:502
lr : __fortify_strlen include/linux/fortify-string.h:196 [inline]
lr : getname_kernel+0x34/0x2bc fs/namei.c:225
sp : ffff8000210677e0
x29: ffff800021067800 x28: 1fffe000197d7a1e x27: 1fffe0001ec1e78b
x26: dfff800000000000 x25: 1fffe0001be9ff42 x24: dfff800000000000
x23: dfff800000000000 x22: ffff70000420cf10 x21: 0000000000020002
x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000
x17: 0000000000000000 x16: ffff800011b90080 x15: 000000000004ffff
x14: 0000000000000001 x13: 1ffff0000420cee8 x12: 0000000000000000
x11: 0000000000000000 x10: dfff800000000000 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : ffff80001865fb30 x4 : 0000000000000008 x3 : ffff8000082d44b4
x2 : 0000000000000000 x1 : 0000000000020002 x0 : 0000000000000000
Call trace:
strlen+0x28/0x84 lib/string.c:502
__fortify_strlen include/linux/fortify-string.h:196 [inline]
getname_kernel+0x34/0x2bc fs/namei.c:225
filp_open+0x8c/0x1cc fs/open.c:1281
nvmet_file_ns_enable+0x88/0x2f8 drivers/nvme/target/io-cmd-file.c:41
nvmet_ns_enable+0xe4/0x724 drivers/nvme/target/core.c:576
nvmet_ns_enable_store+0xd4/0x170 drivers/nvme/target/configfs.c:548
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x260/0x338 fs/configfs/file.c:229
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x3c8/0x7c8 fs/read_write.c:584
ksys_write+0x12c/0x228 fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__arm64_sys_write+0x7c/0x90 fs/read_write.c:646
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
Code: aa0003e8 f2fbffea d343fd0b 1200090c (38ea696b)
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
0: aa0003e8 mov x8, x0
4: f2fbffea movk x10, #0xdfff, lsl #48
8: d343fd0b lsr x11, x8, #3
c: 1200090c and w12, w8, #0x7
* 10: 38ea696b ldrsb w11, [x11, x10] <-- trapping instruction


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