general protection fault in dummy_udc_start

Status: premoderation: reported syz repro on 2026/07/24 15:05
Reported-by: syzbot+84bb30fa48a826953ed8@syzkaller.appspotmail.com
First crash: 14d, last: 10m
Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 BUG: unable to handle kernel paging request in dummy_udc_start 8 syz, C 186 1h47m 14d 0/3 upstream: reported C repro on 2026/07/24 22:21
android-6-1 general protection fault in dummy_udc_start 2 syz 219 40m 14d 0/2 premoderation: reported syz repro on 2026/07/24 17:41
upstream general protection fault in dummy_udc_start usb prio:low 10 syz, C error 2844 now 10d 0/29 upstream: reported C repro on 2026/07/28 14:15
android-5-15 general protection fault in dummy_udc_start 2 syz 298 1h12m 13d 0/2 premoderation: reported syz repro on 2026/07/25 06:03
android-5-10 general protection fault in dummy_udc_start 2 syz, C 429 15m 9d14h 0/2 upstream: reported C repro on 2026/07/29 14:38
linux-6.6 general protection fault in dummy_udc_start 2 syz, C 72 15h27m 13d 0/2 upstream: reported C repro on 2026/07/25 17:39
linux-5.15 general protection fault in dummy_udc_start origin:upstream 2 syz, C 60 16h41m 13d 0/3 upstream: reported C repro on 2026/07/25 16:07

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 410 Comm: syz.0.17 Not tainted syzkaller #0 67f5df147bfe8fe71cdb2f404f013e40b3f12e05
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:dummy_udc_start+0xd1/0x1f0 drivers/usb/gadget/udc/dummy_hcd.c:1003
Code: 41 83 ff 03 74 18 41 83 ff 05 0f 85 94 00 00 00 e8 24 05 ce fd eb 0c e8 1d 05 ce fd eb 05 e8 16 05 ce fd 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 f7 e8 70 c9 26 fe 4d 8b 36 4c 89 f7 e8
RSP: 0018:ffffc900011af818 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888121f94010 RCX: ffff88811c2b9300
RDX: 0000000000000000 RSI: ffffffff87a4b360 RDI: 0000000000000003
RBP: ffffc900011af840 R08: ffff88811c2b9300 R09: 0000000000000004
R10: 0000000000000005 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000003
FS:  000055555b561500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f802885f7cc CR3: 0000000103f8c000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 usb_gadget_udc_start_locked drivers/usb/gadget/udc/core.c:1227 [inline]
 gadget_bind_driver+0x3e1/0x9c0 drivers/usb/gadget/udc/core.c:1646
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x2e1/0x8b0 drivers/base/dd.c:657
 __driver_probe_device+0x193/0x280 drivers/base/dd.c:799
 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829
 __driver_attach+0x422/0x5e0 drivers/base/dd.c:1215
 bus_for_each_dev+0x249/0x2d0 drivers/base/bus.c:370
 driver_attach+0x46/0x50 drivers/base/dd.c:1233
 bus_add_driver+0x393/0x730 drivers/base/bus.c:675
 driver_register+0x2b7/0x3c0 drivers/base/driver.c:246
 usb_gadget_register_driver_owner+0xfc/0x270 drivers/usb/gadget/udc/core.c:1731
 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:596 [inline]
 raw_ioctl+0x144c/0x37a0 drivers/usb/gadget/legacy/raw_gadget.c:1307
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0x135/0x1b0 fs/ioctl.c:893
 __x64_sys_ioctl+0x7f/0xa0 fs/ioctl.c:893
 x64_sys_call+0x1878/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fd46659dd6b
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007ffc543045b0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007fd46659dd6b
RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000009
RBP: 00007ffc54305680 R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00002000000006c0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dummy_udc_start+0xd1/0x1f0 drivers/usb/gadget/udc/dummy_hcd.c:1003
Code: 41 83 ff 03 74 18 41 83 ff 05 0f 85 94 00 00 00 e8 24 05 ce fd eb 0c e8 1d 05 ce fd eb 05 e8 16 05 ce fd 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 f7 e8 70 c9 26 fe 4d 8b 36 4c 89 f7 e8
RSP: 0018:ffffc900011af818 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888121f94010 RCX: ffff88811c2b9300
RDX: 0000000000000000 RSI: ffffffff87a4b360 RDI: 0000000000000003
RBP: ffffc900011af840 R08: ffff88811c2b9300 R09: 0000000000000004
R10: 0000000000000005 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000003
FS:  000055555b561500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8028b50300 CR3: 0000000103f8c000 CR4: 00000000003526b0
----------------
Code disassembly (best guess):
   0:	41 83 ff 03          	cmp    $0x3,%r15d
   4:	74 18                	je     0x1e
   6:	41 83 ff 05          	cmp    $0x5,%r15d
   a:	0f 85 94 00 00 00    	jne    0xa4
  10:	e8 24 05 ce fd       	call   0xfdce0539
  15:	eb 0c                	jmp    0x23
  17:	e8 1d 05 ce fd       	call   0xfdce0539
  1c:	eb 05                	jmp    0x23
  1e:	e8 16 05 ce fd       	call   0xfdce0539
  23:	4c 89 f0             	mov    %r14,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 f7             	mov    %r14,%rdi
  34:	e8 70 c9 26 fe       	call   0xfe26c9a9
  39:	4d 8b 36             	mov    (%r14),%r14
  3c:	4c 89 f7             	mov    %r14,%rdi
  3f:	e8                   	.byte 0xe8

Crashes (487):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/06 21:51 android16-6.12 749a6f9d41aa c38879ea .config strace log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/02 08:51 android16-6.12 1a138e24e292 e611ffe1 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/07/29 19:57 android16-6.12 f1c9c21d1c2f 6ef5c1e2 .config strace log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/07/29 18:12 android16-6.12 f1c9c21d1c2f 6ef5c1e2 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/07/29 14:18 android16-6.12 6f69867ef141 19622d9d .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/07/28 12:51 android16-6.12 7b9e76cc9df5 45ae1df4 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/08 04:30 android16-6.12 b54741372957 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/08 03:05 android16-6.12 b54741372957 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/08 02:46 android16-6.12 b54741372957 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/08 02:42 android16-6.12 b54741372957 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/08 00:59 android16-6.12 b54741372957 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/07 23:53 android16-6.12 b54741372957 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/07 22:28 android16-6.12 282da3f968e5 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/07 21:17 android16-6.12 282da3f968e5 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/07 20:00 android16-6.12 282da3f968e5 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/07 18:52 android16-6.12 282da3f968e5 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/07 17:42 android16-6.12 282da3f968e5 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/07 16:29 android16-6.12 282da3f968e5 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/07 12:13 android16-6.12 282da3f968e5 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/07 10:28 android16-6.12 282da3f968e5 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/07 10:27 android16-6.12 282da3f968e5 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/07 08:43 android16-6.12 282da3f968e5 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/07 07:00 android16-6.12 282da3f968e5 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/07 05:35 android16-6.12 749a6f9d41aa c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/07 03:41 android16-6.12 749a6f9d41aa c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/06 23:04 android16-6.12 749a6f9d41aa c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/06 20:38 android16-6.12 749a6f9d41aa c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/06 18:48 android16-6.12 749a6f9d41aa c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/06 15:29 android16-6.12 749a6f9d41aa c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/06 14:40 android16-6.12 749a6f9d41aa c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/06 13:01 android16-6.12 749a6f9d41aa cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/06 11:28 android16-6.12 749a6f9d41aa cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/06 10:04 android16-6.12 1d5d2bee38d2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/06 08:33 android16-6.12 1d5d2bee38d2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/06 06:48 android16-6.12 1d5d2bee38d2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/06 05:46 android16-6.12 1d5d2bee38d2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/06 04:29 android16-6.12 1d5d2bee38d2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/06 02:33 android16-6.12 1d5d2bee38d2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/06 01:32 android16-6.12 1d5d2bee38d2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/05 23:56 android16-6.12 1d5d2bee38d2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/05 22:31 android16-6.12 1d5d2bee38d2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/05 20:51 android16-6.12 1d5d2bee38d2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/05 20:07 android16-6.12 1d5d2bee38d2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/05 19:43 android16-6.12 1d5d2bee38d2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/05 19:36 android16-6.12 1d5d2bee38d2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/05 18:28 android16-6.12 1d5d2bee38d2 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/05 16:25 android16-6.12 f068f96e8cc3 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/05 15:09 android16-6.12 f068f96e8cc3 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
2026/08/05 12:20 android16-6.12 f068f96e8cc3 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust general protection fault in dummy_udc_start
* Struck through repros no longer work on HEAD.