BUG: unable to handle kernel paging request in iowrite32

Status: moderation: reported on 2026/08/10 00:35
Subsystems: usb
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+62d479e0d4edccb2e4cf@syzkaller.appspotmail.com
First crash: 5d20h, last: 5d20h
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
a710f326 repro-c Reproduced: ✅
❓ BUG: unable to handle kernel paging request in iowrite32 2026/08/10 07:52 2026/08/10 08:20 2026/08/10 08:47 5d63f80b
0b2e5d22 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ✅ ❓ BUG: unable to handle kernel paging request in iowrite32 2026/08/09 18:07 2026/08/09 18:07 2026/08/09 18:38 5d63f80b
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/08/10 08:58 28m nogikh@google.com upstream error

Sample crash report:
thunderbolt 0000:00:07.0: timeout resetting host router
BUG: unable to handle page fault for address: ffffc90000f70208
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 1b000067 P4D 1b000067 PUD 1c2b9067 PMD 30b6b067 PTE 0
Oops: Oops: 0002 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5323 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:writel arch/x86/include/asm/io.h:67 [inline]
RIP: 0010:iowrite32+0x1e/0x80 lib/iomap.c:225
Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 53 48 89 f3 89 fd e8 00 ad e7 fc 48 81 fb 00 00 04 00 72 09 e8 f2 ac e7 fc <89> 2b eb 52 48 81 fb 01 00 01 00 72 0c e8 e0 ac e7 fc 89 e8 89 da
RSP: 0018:ffffc9000f73f7f0 EFLAGS: 00010287
RAX: ffffffff84df75ce RBX: ffffc90000f70208 RCX: 0000000000100000
RDX: ffffc9000ee92000 RSI: 00000000000b3ba8 RDI: 00000000000b3ba9
RBP: 00000000ffffffff R08: ffffc9000f73f3a7 R09: 1ffff92001ee7e74
R10: dffffc0000000000 R11: fffff52001ee7e75 R12: 1ffff110025ead11
R13: ffffc90000f70208 R14: 0000000000000000 R15: 0000000000000001
FS:  00007f59dd5f56c0(0000) GS:ffff88808c540000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc90000f70208 CR3: 00000000430ad000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 nhi_mask_interrupt drivers/thunderbolt/nhi.c:-1 [inline]
 nhi_disable_interrupts+0x150/0x350 drivers/thunderbolt/nhi.c:162
 nhi_probe+0x2be/0x880 drivers/thunderbolt/nhi.c:1211
 nhi_pci_probe+0x46b/0x580 drivers/thunderbolt/pci.c:479
 local_pci_probe drivers/pci/pci-driver.c:332 [inline]
 pci_call_probe drivers/pci/pci-driver.c:394 [inline]
 __pci_device_probe drivers/pci/pci-driver.c:455 [inline]
 pci_device_probe+0x431/0xc90 drivers/pci/pci-driver.c:489
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 device_driver_attach+0xe0/0x1d0 drivers/base/dd.c:1203
 bind_store+0x1d0/0x220 drivers/base/bus.c:267
 kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 ksys_write+0x150/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f59e119e019
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:00007f59dd5f4fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f59e1425fa0 RCX: 00007f59e119e019
RDX: 000000000000000d RSI: 00002000000001c0 RDI: 0000000000000004
RBP: 00007f59e123500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f59e1426038 R14: 00007f59e1425fa0 R15: 00007fffc2eb28b8
 </TASK>
Modules linked in:
CR2: ffffc90000f70208
---[ end trace 0000000000000000 ]---
RIP: 0010:writel arch/x86/include/asm/io.h:67 [inline]
RIP: 0010:iowrite32+0x1e/0x80 lib/iomap.c:225
Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 53 48 89 f3 89 fd e8 00 ad e7 fc 48 81 fb 00 00 04 00 72 09 e8 f2 ac e7 fc <89> 2b eb 52 48 81 fb 01 00 01 00 72 0c e8 e0 ac e7 fc 89 e8 89 da
RSP: 0018:ffffc9000f73f7f0 EFLAGS: 00010287
RAX: ffffffff84df75ce RBX: ffffc90000f70208 RCX: 0000000000100000
RDX: ffffc9000ee92000 RSI: 00000000000b3ba8 RDI: 00000000000b3ba9
RBP: 00000000ffffffff R08: ffffc9000f73f3a7 R09: 1ffff92001ee7e74
R10: dffffc0000000000 R11: fffff52001ee7e75 R12: 1ffff110025ead11
R13: ffffc90000f70208 R14: 0000000000000000 R15: 0000000000000001
FS:  00007f59dd5f56c0(0000) GS:ffff88808c540000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc90000f70208 CR3: 00000000430ad000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	90                   	nop
   1:	90                   	nop
   2:	90                   	nop
   3:	90                   	nop
   4:	90                   	nop
   5:	90                   	nop
   6:	90                   	nop
   7:	90                   	nop
   8:	90                   	nop
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	f3 0f 1e fa          	endbr64
  10:	55                   	push   %rbp
  11:	53                   	push   %rbx
  12:	48 89 f3             	mov    %rsi,%rbx
  15:	89 fd                	mov    %edi,%ebp
  17:	e8 00 ad e7 fc       	call   0xfce7ad1c
  1c:	48 81 fb 00 00 04 00 	cmp    $0x40000,%rbx
  23:	72 09                	jb     0x2e
  25:	e8 f2 ac e7 fc       	call   0xfce7ad1c
* 2a:	89 2b                	mov    %ebp,(%rbx) <-- trapping instruction
  2c:	eb 52                	jmp    0x80
  2e:	48 81 fb 01 00 01 00 	cmp    $0x10001,%rbx
  35:	72 0c                	jb     0x43
  37:	e8 e0 ac e7 fc       	call   0xfce7ad1c
  3c:	89 e8                	mov    %ebp,%eax
  3e:	89 da                	mov    %ebx,%edx

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/04 20:40 upstream 562bfb501c54 3c5eaa21 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root BUG: unable to handle kernel paging request in iowrite32
* Struck through repros no longer work on HEAD.