[v6.6] general protection fault in getname_kernel

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 80dfb0405055 Linux 6.6.149
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11e8d7b9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0bc3d90c30838b5
dashboard link: https://syzkaller.appspot.com/bug?extid=7ad36bea639f2d542633
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7fa1954ca6a5/disk-80dfb040.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8274c89c5b62/vmlinux-80dfb040.xz
kernel image: https://storage.googleapis.com/syzbot-assets/156d3ce60046/bzImage-80dfb040.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7ad36b...@syzkaller.appspotmail.com

nvmet: adding nsid 1 to subsystem testnqn
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: 10265 Comm: syz.5.1160 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:strlen+0x29/0x70 lib/string.c:425
Code: da f3 0f 1e fa 41 57 41 56 41 54 53 48 c7 c0 ff ff ff ff 49 be 00 00 00 00 00 fc ff df 48 89 fb 49 89 c7 48 89 d8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 75 11 48 ff c3 49 8d 47 01 42 80 7c 3f 01 00
RSP: 0018:ffffc900127ff9c0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000d6c4000 RSI: 00000000000013d4 RDI: 0000000000000000
RBP: ffffc900127ffaf8 R08: ffffffff8e8c7aef R09: 1ffffffff1d18f5d
R10: dffffc0000000000 R11: fffffbfff1d18f5e R12: 1ffff920024fff48
R13: dffffc0000000000 R14: dffffc0000000000 R15: ffffffffffffffff
FS: 00007f5a57cf06c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c31a99d CR3: 00000000662c5000 CR4: 00000000003506f0
Call Trace:
<TASK>
__fortify_strlen include/linux/fortify-string.h:228 [inline]
getname_kernel+0x28/0x2f0 fs/namei.c:226
filp_open+0x88/0x1e0 fs/open.c:1383
nvmet_file_ns_enable+0x74/0x330 drivers/nvme/target/io-cmd-file.c:41
nvmet_ns_enable+0xf4/0x8c0 drivers/nvme/target/core.c:578
nvmet_ns_enable_store+0xd8/0x170 drivers/nvme/target/configfs.c:549
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x312/0x400 fs/configfs/file.c:229
call_write_iter include/linux/fs.h:2018 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x474/0x9a0 fs/read_write.c:584
ksys_write+0x151/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5a56d9e0d9
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:00007f5a57cf0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5a57025fa0 RCX: 00007f5a56d9e0d9
RDX: 0000000000000001 RSI: 0000200000000580 RDI: 0000000000000004
RBP: 00007f5a56e35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5a57026038 R14: 00007f5a57025fa0 R15: 00007ffdf2fd3808
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:strlen+0x29/0x70 lib/string.c:425
Code: da f3 0f 1e fa 41 57 41 56 41 54 53 48 c7 c0 ff ff ff ff 49 be 00 00 00 00 00 fc ff df 48 89 fb 49 89 c7 48 89 d8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 75 11 48 ff c3 49 8d 47 01 42 80 7c 3f 01 00
RSP: 0018:ffffc900127ff9c0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000d6c4000 RSI: 00000000000013d4 RDI: 0000000000000000
RBP: ffffc900127ffaf8 R08: ffffffff8e8c7aef R09: 1ffffffff1d18f5d
R10: dffffc0000000000 R11: fffffbfff1d18f5e R12: 1ffff920024fff48
R13: dffffc0000000000 R14: dffffc0000000000 R15: ffffffffffffffff
FS: 00007f5a57cf06c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007eff987eb7c0 CR3: 00000000662c5000 CR4: 00000000003506e0
----------------
Code disassembly (best guess), 1 bytes skipped:
0: f3 0f 1e fa endbr64
4: 41 57 push %r15
6: 41 56 push %r14
8: 41 54 push %r12
a: 53 push %rbx
b: 48 c7 c0 ff ff ff ff mov $0xffffffffffffffff,%rax
12: 49 be 00 00 00 00 00 movabs $0xdffffc0000000000,%r14
19: fc ff df
1c: 48 89 fb mov %rdi,%rbx
1f: 49 89 c7 mov %rax,%r15
22: 48 89 d8 mov %rbx,%rax
25: 48 c1 e8 03 shr $0x3,%rax
* 29: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax <-- trapping instruction
2e: 84 c0 test %al,%al
30: 75 11 jne 0x43
32: 48 ff c3 inc %rbx
35: 49 8d 47 01 lea 0x1(%r15),%rax
39: 42 80 7c 3f 01 00 cmpb $0x0,0x1(%rdi,%r15,1)


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