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

[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=13d06cc6580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=60f90b3b9534f4fc4759
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/9a6fe2a54d0f/disk-fb28aa72.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/742b23a1d931/vmlinux-fb28aa72.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b3f257c16d2e/bzImage-fb28aa72.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+60f90b...@syzkaller.appspotmail.com

BUG: unable to handle page fault for address: 000000000001c000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 2ecf8067 P4D 2ecf8067 PUD 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4371 Comm: kworker/0:8 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events azx_probe_work
RIP: 0010:readw arch/x86/include/asm/io.h:60 [inline]
RIP: 0010:snd_hdac_reg_readw include/sound/hdaudio.h:449 [inline]
RIP: 0010:azx_first_init sound/pci/hda/hda_intel.c:1924 [inline]
RIP: 0010:azx_probe_continue+0xcbd/0x26a0 sound/pci/hda/hda_intel.c:2342
Code: 80 20 f7 48 8b 7c 24 08 e8 50 f8 2c fc 48 b8 00 00 00 00 00 fc ff df 41 80 7c 05 00 00 74 08 4c 89 ff e8 76 a8 ba f9 49 8b 07 <66> 44 8b 28 0f 1f 44 00 00 e8 a5 7b 69 f9 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc9000476fba0 EFLAGS: 00010246
RAX: 000000000001c000 RBX: ffff888073270028 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: 00000000ffffffff
RBP: ffff8880732707a8 R08: ffffffff90b1037f R09: 1ffffffff216206f
R10: dffffc0000000000 R11: fffffbfff2162070 R12: dffffc0000000000
R13: 1ffff1100e64e009 R14: 00000000ffffffea R15: ffff888073270048
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000001c000 CR3: 000000005b744000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Modules linked in:
CR2: 000000000001c000
---[ end trace 0000000000000000 ]---
RIP: 0010:readw arch/x86/include/asm/io.h:60 [inline]
RIP: 0010:snd_hdac_reg_readw include/sound/hdaudio.h:449 [inline]
RIP: 0010:azx_first_init sound/pci/hda/hda_intel.c:1924 [inline]
RIP: 0010:azx_probe_continue+0xcbd/0x26a0 sound/pci/hda/hda_intel.c:2342
Code: 80 20 f7 48 8b 7c 24 08 e8 50 f8 2c fc 48 b8 00 00 00 00 00 fc ff df 41 80 7c 05 00 00 74 08 4c 89 ff e8 76 a8 ba f9 49 8b 07 <66> 44 8b 28 0f 1f 44 00 00 e8 a5 7b 69 f9 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc9000476fba0 EFLAGS: 00010246
RAX: 000000000001c000 RBX: ffff888073270028 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: 00000000ffffffff
RBP: ffff8880732707a8 R08: ffffffff90b1037f R09: 1ffffffff216206f
R10: dffffc0000000000 R11: fffffbfff2162070 R12: dffffc0000000000
R13: 1ffff1100e64e009 R14: 00000000ffffffea R15: ffff888073270048
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000001c000 CR3: 000000005b744000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 80 20 f7 andb $0xf7,(%rax)
3: 48 8b 7c 24 08 mov 0x8(%rsp),%rdi
8: e8 50 f8 2c fc call 0xfc2cf85d
d: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
14: fc ff df
17: 41 80 7c 05 00 00 cmpb $0x0,0x0(%r13,%rax,1)
1d: 74 08 je 0x27
1f: 4c 89 ff mov %r15,%rdi
22: e8 76 a8 ba f9 call 0xf9baa89d
27: 49 8b 07 mov (%r15),%rax
* 2a: 66 44 8b 28 mov (%rax),%r13w <-- trapping instruction
2e: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
33: e8 a5 7b 69 f9 call 0xf9697bdd
38: 48 rex.W
39: b8 00 00 00 00 mov $0x0,%eax
3e: 00 fc add %bh,%ah


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