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: 19d, last: 1d04h
✨ 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 (4)
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 5d19h 13d 0/2 premoderation: reported on 2026/07/30 11:35
android-5-10 general protection fault in dummy_udc_stop 2 1 18d 18d 0/2 premoderation: reported on 2026/07/25 11:23
android-6-12 general protection fault in dummy_udc_stop 2 2 11d 18d 0/1 premoderation: reported on 2026/07/26 08:20
android-6-1 general protection fault in dummy_udc_stop 2 2 18h09m 10d 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: 1 UID: 0 PID: 23020 Comm: syz.0.3965 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
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 e2 07 3b 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 ec 49 ee 03 48
RSP: 0018:ffffc9000e0978e0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff87cf6b62
RDX: 0000000000000000 RSI: ffffffff87cf6b9e RDI: ffff88802131d290
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000005
R10: 0000000000000003 R11: 0000000000000000 R12: ffff888039a80050
R13: ffff88802aee7540 R14: ffff88802131cc00 R15: ffffffff8cb78a40
FS:  0000000000000000(0000) GS:ffff888123eec000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f088cc0a09d CR3: 0000000073fea000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
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
 raw_release+0x19b/0x260 drivers/usb/gadget/legacy/raw_gadget.c:463
 __fput+0x3ff/0xb50 fs/file_table.c:512
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x951/0x2ae0 kernel/exit.c:1009
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1152
 get_signal+0x1ec7/0x21e0 kernel/signal.c:3046
 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x139/0x6f0 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:318 [inline]
 do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd9b399e0d9
Code: Unable to access opcode bytes at 0x7fd9b399e0af.
RSP: 002b:00007fd9b489d0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fd9b3c26098 RCX: 00007fd9b399e0d9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd9b3c26098
RBP: 00007fd9b3c26090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd9b3c26128 R14: 00007ffedd2ada80 R15: 00007ffedd2adb68
 </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 e2 07 3b 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 ec 49 ee 03 48
RSP: 0018:ffffc9000e0978e0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff87cf6b62
RDX: 0000000000000000 RSI: ffffffff87cf6b9e RDI: ffff88802131d290
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000005
R10: 0000000000000003 R11: 0000000000000000 R12: ffff888039a80050
R13: ffff88802aee7540 R14: ffff88802131cc00 R15: ffffffff8cb78a40
FS:  0000000000000000(0000) GS:ffff888123dec000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9e9563cd58 CR3: 0000000073fea000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
----------------
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 e2 07 3b fa       	call   0xfa3b07fb
  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 ec 49 ee 03       	call   0x3ee4a2b
  3f:	48                   	rex.W

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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
2026/07/29 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
2026/08/08 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
2026/08/04 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.