general protection fault in usbtest_probe

Status: upstream: reported C repro on 2026/07/29 00:19
Subsystems: usb
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+7e1e5911f9eac50bedc7@syzkaller.appspotmail.com
First crash: 5d16h, last: 1d16h
✨ AI Patch Versions (2)
Version Stage Reported Report Link Job
1 upstream 2026/07/29 09:19 Discussion 9e476ca5-99d1-47d2-b9d1-f3b501897179
1 moderation 2026/07/29 08:26 Discussion 9e476ca5-99d1-47d2-b9d1-f3b501897179
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
9e476ca5 patching general protection fault in usbtest_probe 2026/07/29 07:31 2026/07/29 07:31 2026/07/29 08:26 19622d9d

			
		
6b0687ea assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ general protection fault in usbtest_probe 2026/07/25 00:42 2026/07/25 00:42 2026/07/25 00:45 1bdb5c57

			
		
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] usb: usbtest: fix NULL pointer dereference in usbtest_probe 1 (1) 2026/07/29 09:19
[syzbot] [usb?] general protection fault in usbtest_probe 0 (1) 2026/07/29 00:19
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 general protection fault in usbtest_probe origin:upstream 2 syz, C 6 2d21h 5d14h 0/3 upstream: reported C repro on 2026/07/24 21:55
linux-6.1 BUG: unable to handle kernel paging request in usbtest_probe 8 5 5d11h 5d12h 0/3 upstream: reported on 2026/07/24 23:34

Sample crash report:
usb 5-1: New USB device found, idVendor=0547, idProduct=2235, bcdDevice= 0.00
usb 5-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 5-1: Product: syz
usb 5-1: Manufacturer: syz
usb 5-1: SerialNumber: syz
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 UID: 0 PID: 29 Comm: kworker/1:0 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
Workqueue: usb_hub_wq hub_event
RIP: 0010:usbtest_probe+0x3b9/0x1280 drivers/usb/misc/usbtest.c:2822
Code: e9 46 fa 45 85 ff 79 5e e8 34 ef 46 fa 48 8b 84 24 80 00 00 00 48 8d 58 0a 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <0f> b6 04 02 48 89 da 83 e2 07 38 d0 7f 08 84 c0 0f 85 58 0d 00 00
RSP: 0018:ffffc90000686fc8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 000000000000000a RCX: ffffffff87c37102
RDX: 0000000000000001 RSI: ffffffff87c3710c RDI: ffff88801f69a540
RBP: ffff88802bf65910 R08: 0000000000000005 R09: 0000000000000000
R10: 00000000ffffffff R11: 000000000000758b R12: ffff88816db048b0
R13: ffff88803724fed0 R14: ffff88803724fe00 R15: 00000000ffffffff
FS:  0000000000000000(0000) GS:ffff8880d5edc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f87747eb580 CR3: 000000002ad51000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x64/0x160 drivers/base/bus.c:620
 device_add+0x121d/0x1970 drivers/base/core.c:3772
 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268
 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x64/0x160 drivers/base/bus.c:620
 device_add+0x121d/0x1970 drivers/base/core.c:3772
 usb_new_device.cold+0x685/0x115c drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x30a3/0x4a60 drivers/usb/core/hub.c:5953
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:usbtest_probe+0x3b9/0x1280 drivers/usb/misc/usbtest.c:2822
Code: e9 46 fa 45 85 ff 79 5e e8 34 ef 46 fa 48 8b 84 24 80 00 00 00 48 8d 58 0a 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <0f> b6 04 02 48 89 da 83 e2 07 38 d0 7f 08 84 c0 0f 85 58 0d 00 00
RSP: 0018:ffffc90000686fc8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 000000000000000a RCX: ffffffff87c37102
RDX: 0000000000000001 RSI: ffffffff87c3710c RDI: ffff88801f69a540
RBP: ffff88802bf65910 R08: 0000000000000005 R09: 0000000000000000
R10: 00000000ffffffff R11: 000000000000758b R12: ffff88816db048b0
R13: ffff88803724fed0 R14: ffff88803724fe00 R15: 00000000ffffffff
FS:  0000000000000000(0000) GS:ffff8880d5edc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f87747eb580 CR3: 000000002a8fe000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	46 fa                	rex.RX cli
   2:	45 85 ff             	test   %r15d,%r15d
   5:	79 5e                	jns    0x65
   7:	e8 34 ef 46 fa       	call   0xfa46ef40
   c:	48 8b 84 24 80 00 00 	mov    0x80(%rsp),%rax
  13:	00
  14:	48 8d 58 0a          	lea    0xa(%rax),%rbx
  18:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1f:	fc ff df
  22:	48 89 da             	mov    %rbx,%rdx
  25:	48 c1 ea 03          	shr    $0x3,%rdx
* 29:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax <-- trapping instruction
  2d:	48 89 da             	mov    %rbx,%rdx
  30:	83 e2 07             	and    $0x7,%edx
  33:	38 d0                	cmp    %dl,%al
  35:	7f 08                	jg     0x3f
  37:	84 c0                	test   %al,%al
  39:	0f 85 58 0d 00 00    	jne    0xd97

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/28 19:33 upstream 3b5f4b83c4ab 4a865b71 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream general protection fault in usbtest_probe
2026/07/26 12:33 upstream 3dab139d4795 4a865b71 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream general protection fault in usbtest_probe
2026/07/24 21:56 linux-next cc2b5f627e8c 05b26a28 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce general protection fault in usbtest_probe
2026/07/26 18:29 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 365f9c7a6b81 492bab15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in usbtest_probe
2026/07/25 18:17 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci b66b0005b6ce 492bab15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in usbtest_probe
2026/07/24 22:38 upstream 48a5a7ab8d6a 05b26a28 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root general protection fault in usbtest_probe
2026/07/24 22:38 upstream 48a5a7ab8d6a 05b26a28 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root general protection fault in usbtest_probe
2026/07/24 22:37 upstream 48a5a7ab8d6a 05b26a28 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root general protection fault in usbtest_probe
2026/07/24 22:37 upstream 48a5a7ab8d6a 05b26a28 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root general protection fault in usbtest_probe
2026/07/24 20:41 upstream 48a5a7ab8d6a 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 general protection fault in usbtest_probe
2026/07/24 20:40 upstream 48a5a7ab8d6a 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 general protection fault in usbtest_probe
2026/07/24 20:14 linux-next cc2b5f627e8c 05b26a28 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce general protection fault in usbtest_probe
2026/07/24 20:13 linux-next cc2b5f627e8c 05b26a28 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce general protection fault in usbtest_probe
* Struck through repros no longer work on HEAD.