general protection fault in dummy_udc_stop

Status: upstream: reported on 2026/08/02 00:01
Subsystems: usb
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+366177ceada8026bb3a6@syzkaller.appspotmail.com
First crash: 54d, last: 22d
✨ AI Jobs (3)
ID Workflow Result Correct Bug Created Started Finished Revision
ffab3533 repro 💥 general protection fault in dummy_udc_stop 2026/08/11 14:55 2026/08/11 15:37 2026/08/11 17:18 f8d35649
4896cb70 repro-c Reproduced: ✅ general protection fault in dummy_udc_stop 2026/08/09 18:24 2026/08/09 18:38 2026/08/09 18:58 5d63f80b
d819bdab assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ general protection fault in dummy_udc_stop 2026/07/27 01:53 2026/07/27 01:53 2026/07/27 01:58 492bab15
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [usb?] general protection fault in dummy_udc_stop 0 (1) 2026/08/02 00:01
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 general protection fault in dummy_udc_stop 2 3 41d 49d 0/2 premoderation: reported on 2026/07/30 11:35
android-5-10 general protection fault in dummy_udc_stop 2 7 22d 54d 0/2 premoderation: reported on 2026/07/25 11:23
linux-6.1 BUG: unable to handle kernel paging request in dummy_udc_stop 8 5 22d 31d 0/3 upstream: reported on 2026/08/17 08:31
android-6-12 general protection fault in dummy_udc_stop 2 5 24d 53d 0/1 premoderation: reported on 2026/07/26 08:20
android-6-1 general protection fault in dummy_udc_stop 2 3 25d 45d 0/2 premoderation: reported on 2026/08/02 20:29
Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/08/10 07:30 1h00m nogikh@google.com upstream report log

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 20645 Comm: syz.7.3215 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
RIP: 0010:dummy_udc_stop+0x8f/0x180 drivers/usb/gadget/udc/dummy_hcd.c:1053
Code: c1 ea 03 80 3c 02 00 0f 85 f9 00 00 00 48 8b 9b 90 06 00 00 e8 c2 9c 30 fa 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 c5 00 00 00 48 8b 1b 48 89 df e8 bc ed f2 03 48
RSP: 0018:ffffc900058ffc28 EFLAGS: 00010256
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff87da680e RDI: ffff88802a28d290
RBP: 0000000000000002 R08: 0000000000000005 R09: 0000000000000005
R10: 0000000000000002 R11: 0000000000000000 R12: ffffffff90478260
R13: ffff88802ba43540 R14: ffff88802a28cc00 R15: ffffffff8cd9aa20
FS:  00005555877ae500(0000) GS:ffff888123b7b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdddcc2d0fa CR3: 000000007e66e000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 usb_gadget_udc_stop_locked drivers/usb/gadget/udc/core.c:1265 [inline]
 gadget_unbind_driver+0x2ca/0x4f0 drivers/usb/gadget/udc/core.c:1727
 device_remove+0xcb/0x180 drivers/base/dd.c:616
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1372
 driver_detach+0xd8/0x1b0 drivers/base/dd.c:1435
 bus_remove_driver+0x13b/0x2e0 drivers/base/bus.c:832
 driver_unregister+0x76/0xb0 drivers/base/driver.c:202
 usb_gadget_unregister_driver+0x49/0x70 drivers/usb/gadget/udc/core.c:1784
 dev_release+0x132/0x1b0 drivers/usb/gadget/legacy/inode.c:1198
 __fput+0x3ff/0xb50 fs/file_table.c:512
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1d8/0x700 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
 do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcbfe99e0d9
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:00007fff8af773e8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fff8af774d0 RCX: 00007fcbfe99e0d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00000000001c14b7 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2ed20000 R11: 0000000000000246 R12: 00007fff8af77510
R13: 00007fcbfec25fac R14: 00000000001c1e68 R15: 00007fcbfec25fa0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dummy_udc_stop+0x8f/0x180 drivers/usb/gadget/udc/dummy_hcd.c:1053
Code: c1 ea 03 80 3c 02 00 0f 85 f9 00 00 00 48 8b 9b 90 06 00 00 e8 c2 9c 30 fa 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 c5 00 00 00 48 8b 1b 48 89 df e8 bc ed f2 03 48
RSP: 0018:ffffc900058ffc28 EFLAGS: 00010256
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff87da680e RDI: ffff88802a28d290
RBP: 0000000000000002 R08: 0000000000000005 R09: 0000000000000005
R10: 0000000000000002 R11: 0000000000000000 R12: ffffffff90478260
R13: ffff88802ba43540 R14: ffff88802a28cc00 R15: ffffffff8cd9aa20
FS:  00005555877ae500(0000) GS:ffff888123b7b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007feddd67a368 CR3: 000000007e66e000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
   0:	c1 ea 03             	shr    $0x3,%edx
   3:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   7:	0f 85 f9 00 00 00    	jne    0x106
   d:	48 8b 9b 90 06 00 00 	mov    0x690(%rbx),%rbx
  14:	e8 c2 9c 30 fa       	call   0xfa309cdb
  19:	48 89 da             	mov    %rbx,%rdx
  1c:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  23:	fc ff df
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 c5 00 00 00    	jne    0xf9
  34:	48 8b 1b             	mov    (%rbx),%rbx
  37:	48 89 df             	mov    %rbx,%rdi
  3a:	e8 bc ed f2 03       	call   0x3f2edfb
  3f:	48                   	rex.W

Crashes (24):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/24 21:32 upstream 0a0d1d55dad5 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root general protection fault in dummy_udc_stop
2026/08/23 23:42 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root general protection fault in dummy_udc_stop
2026/08/23 23:42 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root general protection fault in dummy_udc_stop
2026/08/23 23:41 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root general protection fault in dummy_udc_stop
2026/08/21 20:21 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root general protection fault in dummy_udc_stop
2026/08/17 13:24 upstream 8d3ae59288f1 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root general protection fault in dummy_udc_stop
2026/08/17 13:13 upstream 8d3ae59288f1 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root general protection fault in dummy_udc_stop
2026/08/17 08:56 upstream dcb68831eac7 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root general protection fault in dummy_udc_stop
2026/08/15 04:17 upstream 2f1baf1fc892 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root general protection fault in dummy_udc_stop
2026/08/12 06:38 upstream f5bbbfec59b4 f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root general protection fault in dummy_udc_stop
2026/08/04 18:29 upstream 848acc8ffe1b d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root general protection fault in dummy_udc_stop
2026/07/25 02:56 upstream 48a5a7ab8d6a 05b26a28 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root general protection fault in dummy_udc_stop
2026/08/21 10:28 upstream 818bebeb63dd 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream general protection fault in dummy_udc_stop
2026/08/21 06:34 upstream 9d2ed026f031 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream general protection fault in dummy_udc_stop
2026/07/29 07:50 upstream fc02acf6ac0c 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream general protection fault in dummy_udc_stop
2026/07/26 08:45 upstream 3dab139d4795 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream general protection fault in dummy_udc_stop
2026/08/26 18:12 upstream 45c13f3f9e3b a2b77b9e .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 general protection fault in dummy_udc_stop
2026/08/08 03:44 upstream 3f008280327b 5d63f80b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 general protection fault in dummy_udc_stop
2026/08/01 07:54 upstream a2cf4ef33184 e611ffe1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 general protection fault in dummy_udc_stop
2026/08/25 07:41 linux-next 4b18edbd8e70 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce general protection fault in dummy_udc_stop
2026/08/18 09:35 linux-next e6664f2b33db 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce general protection fault in dummy_udc_stop
2026/08/17 07:29 linux-next 4477a78374a5 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in dummy_udc_stop
2026/08/04 00:22 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 7235a3e71949 a68cb31b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in dummy_udc_stop
2026/07/28 16:23 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 365f9c7a6b81 19622d9d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in dummy_udc_stop
* Struck through repros no longer work on HEAD.