general protection fault in dummy_udc_start

Status: upstream: reported C repro on 2026/07/29 14:38
Reported-by: syzbot+eeb1871d04483fca386f@syzkaller.appspotmail.com
First crash: 12d, last: 10h38m
▶ ▼ 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 166 6h43m 11d 0/3 upstream: reported C repro on 2026/07/24 22:21
android-6-1 general protection fault in dummy_udc_start 2 syz 162 3h12m 12d 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 2455 7m 8d04h 0/29 upstream: reported C repro on 2026/07/28 14:15
android-5-15 general protection fault in dummy_udc_start 2 syz 263 1h30m 11d 0/2 premoderation: reported syz repro on 2026/07/25 06:03
android-6-12 general protection fault in dummy_udc_start 2 syz 309 34m 12d 0/1 premoderation: reported syz repro on 2026/07/24 15:05
linux-6.6 general protection fault in dummy_udc_start 2 syz, C 57 12h49m 11d 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 45 8h04m 11d 0/3 upstream: reported C repro on 2026/07/25 16:07

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 315 Comm: syz-executor368 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:dummy_udc_start+0xbb/0x210 drivers/usb/gadget/udc/dummy_hcd.c:989
Code: 00 00 ff 24 c5 80 2d 58 85 e8 91 eb 57 fe eb 13 e8 8a eb 57 fe eb 0c e8 83 eb 57 fe eb 05 e8 7c eb 57 fe 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 f7 e8 86 60 92 fe 4d 8b 36 4c 89 f7 e8
RSP: 0018:ffffc90000ca7ae8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888100140010 RCX: ffff88811e6c8000
RDX: 0000000000000000 RSI: ffffffff86917d60 RDI: 0000000000000003
RBP: ffffc90000ca7b10 R08: ffff88811e6c8000 R09: 0000000000000004
R10: 0000000000000005 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000003
FS:  00007faeda5306c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faeda52dff8 CR3: 000000012202e000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 usb_gadget_udc_start_locked drivers/usb/gadget/udc/core.c:1169 [inline]
 udc_bind_to_driver+0x333/0x6d0 drivers/usb/gadget/udc/core.c:1577
 usb_gadget_probe_driver+0x1fc/0x380 drivers/usb/gadget/udc/core.c:1639
 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:548 [inline]
 raw_ioctl+0x114d/0x3040 drivers/usb/gadget/legacy/raw_gadget.c:1255
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0x121/0x1a0 fs/ioctl.c:739
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:739
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7faeda573c2b
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:00007faeda52e0f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007faeda573c2b
RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000004
RBP: 00007faeda52f1d0 R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007faeda623c60 R14: 00007faeda52e1a0 R15: 00002000000005c0
Modules linked in:
---[ end trace 8e0dd27b9e7d5129 ]---
RIP: 0010:dummy_udc_start+0xbb/0x210 drivers/usb/gadget/udc/dummy_hcd.c:989
Code: 00 00 ff 24 c5 80 2d 58 85 e8 91 eb 57 fe eb 13 e8 8a eb 57 fe eb 0c e8 83 eb 57 fe eb 05 e8 7c eb 57 fe 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 f7 e8 86 60 92 fe 4d 8b 36 4c 89 f7 e8
RSP: 0018:ffffc90000ca7ae8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888100140010 RCX: ffff88811e6c8000
RDX: 0000000000000000 RSI: ffffffff86917d60 RDI: 0000000000000003
RBP: ffffc90000ca7b10 R08: ffff88811e6c8000 R09: 0000000000000004
R10: 0000000000000005 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000003
FS:  00007faeda5306c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faeda54eff8 CR3: 000000012202e000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	ff 24 c5 80 2d 58 85 	jmp    *-0x7aa7d280(,%rax,8)
   9:	e8 91 eb 57 fe       	call   0xfe57eb9f
   e:	eb 13                	jmp    0x23
  10:	e8 8a eb 57 fe       	call   0xfe57eb9f
  15:	eb 0c                	jmp    0x23
  17:	e8 83 eb 57 fe       	call   0xfe57eb9f
  1c:	eb 05                	jmp    0x23
  1e:	e8 7c eb 57 fe       	call   0xfe57eb9f
  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 86 60 92 fe       	call   0xfe9260bf
  39:	4d 8b 36             	mov    (%r14),%r14
  3c:	4c 89 f7             	mov    %r14,%rdi
  3f:	e8                   	.byte 0xe8

Crashes (347):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/05 08:24 android13-5.10-lts 0f73d4924a74 52aa2820 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/07/28 18:28 android13-5.10-lts 50b3a256e550 edc8a875 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/07/28 15:08 android13-5.10-lts 50b3a256e550 edc8a875 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/05 00:09 android13-5.10-lts 0f73d4924a74 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/04 23:05 android13-5.10-lts 0f73d4924a74 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/04 21:14 android13-5.10-lts 0f73d4924a74 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/04 20:13 android13-5.10-lts 0f73d4924a74 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/04 18:40 android13-5.10-lts 0f73d4924a74 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/04 16:15 android13-5.10-lts 0f73d4924a74 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/04 11:28 android13-5.10-lts 0f73d4924a74 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/04 09:35 android13-5.10-lts 0f73d4924a74 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/04 07:42 android13-5.10-lts 0f73d4924a74 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/04 06:14 android13-5.10-lts 0f73d4924a74 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/04 04:38 android13-5.10-lts 0f73d4924a74 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/04 03:37 android13-5.10-lts 0f73d4924a74 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 23:30 android13-5.10-lts 0f73d4924a74 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 21:46 android13-5.10-lts 0f73d4924a74 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 17:51 android13-5.10-lts 0f73d4924a74 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 17:50 android13-5.10-lts 0f73d4924a74 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 15:36 android13-5.10-lts 0f73d4924a74 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 12:48 android13-5.10-lts 50b3a256e550 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 12:35 android13-5.10-lts 50b3a256e550 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 10:55 android13-5.10-lts 50b3a256e550 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 08:44 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 07:22 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 07:12 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 06:10 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 05:03 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 03:14 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 01:52 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/03 00:49 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/02 23:25 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/02 22:16 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/02 21:21 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/02 19:40 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/02 18:37 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/02 16:53 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/02 11:55 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/02 11:33 android13-5.10-lts 50b3a256e550 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/07/30 08:26 android13-5.10-lts 50b3a256e550 2377cd3d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/07/30 05:58 android13-5.10-lts 50b3a256e550 6ef5c1e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/07/30 04:43 android13-5.10-lts 50b3a256e550 6ef5c1e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/07/30 00:12 android13-5.10-lts 50b3a256e550 6ef5c1e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/07/29 20:36 android13-5.10-lts 50b3a256e550 6ef5c1e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/07/29 19:30 android13-5.10-lts 50b3a256e550 6ef5c1e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/07/29 16:32 android13-5.10-lts 50b3a256e550 6ef5c1e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/07/29 11:58 android13-5.10-lts 50b3a256e550 19622d9d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/07/29 10:38 android13-5.10-lts 50b3a256e550 19622d9d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/07/29 09:38 android13-5.10-lts 50b3a256e550 19622d9d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/07/29 08:03 android13-5.10-lts 50b3a256e550 19622d9d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
* Struck through repros no longer work on HEAD.