general protection fault in dummy_udc_start

Status: premoderation: reported syz repro on 2026/07/25 06:03
Reported-by: syzbot+3c8fbc79492a7509f815@syzkaller.appspotmail.com
First crash: 12d, last: 6h00m
▶ ▼ 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 178 7m 12d 0/3 upstream: reported C repro on 2026/07/24 22:21
android-6-1 general protection fault in dummy_udc_start 2 syz 192 4h19m 13d 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 2604 now 9d06h 0/29 upstream: reported C repro on 2026/07/28 14:15
android-6-12 general protection fault in dummy_udc_start 2 syz 404 now 13d 0/1 premoderation: reported syz repro on 2026/07/24 15:05
android-5-10 general protection fault in dummy_udc_start 2 syz, C 380 58m 8d06h 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 62 2h29m 12d 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 52 3h45m 12d 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: 0 PID: 408 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:dummy_udc_start+0xbb/0x1d0 drivers/usb/gadget/udc/dummy_hcd.c:1000
Code: 00 00 ff 24 c5 40 20 7c 85 e8 41 0f 40 fe eb 13 e8 3a 0f 40 fe eb 0c e8 33 0f 40 fe eb 05 e8 2c 0f 40 fe 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 f7 e8 86 7e 7f fe 4d 8b 36 4c 89 f7 e8
RSP: 0018:ffffc90000c47aa8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888115d00010 RCX: ffff88810aba13c0
RDX: 0000000000000000 RSI: ffffffff86b49fe0 RDI: 0000000000000003
RBP: ffffc90000c47ad0 R08: ffff88810aba13c0 R09: 0000000000000004
R10: 0000000000000005 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000003
FS:  00007fd9484fb6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd9486a4180 CR3: 000000012197c000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 usb_gadget_udc_start drivers/usb/gadget/udc/core.c:1122 [inline]
 udc_bind_to_driver+0x2af/0x770 drivers/usb/gadget/udc/core.c:1514
 usb_gadget_probe_driver+0x1fc/0x380 drivers/usb/gadget/udc/core.c:1589
 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:549 [inline]
 raw_ioctl+0x114d/0x3040 drivers/usb/gadget/legacy/raw_gadget.c:1256
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0x121/0x1a0 fs/ioctl.c:860
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:860
 x64_sys_call+0x2f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fd9486bacab
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:00007fd9484f8f00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fd9486bacab
RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000004
RBP: 00007fd9484f9fd0 R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000200000000240 R14: 0000000000000003 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 1d2847193d5c0e4e ]---
RIP: 0010:dummy_udc_start+0xbb/0x1d0 drivers/usb/gadget/udc/dummy_hcd.c:1000
Code: 00 00 ff 24 c5 40 20 7c 85 e8 41 0f 40 fe eb 13 e8 3a 0f 40 fe eb 0c e8 33 0f 40 fe eb 05 e8 2c 0f 40 fe 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 f7 e8 86 7e 7f fe 4d 8b 36 4c 89 f7 e8
RSP: 0018:ffffc90000c47aa8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888115d00010 RCX: ffff88810aba13c0
RDX: 0000000000000000 RSI: ffffffff86b49fe0 RDI: 0000000000000003
RBP: ffffc90000c47ad0 R08: ffff88810aba13c0 R09: 0000000000000004
R10: 0000000000000005 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000003
FS:  00007fd9484fb6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f96e3973fd0 CR3: 000000012197c000 CR4: 00000000003506a0
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 40 20 7c 85 	jmp    *-0x7a83dfc0(,%rax,8)
   9:	e8 41 0f 40 fe       	call   0xfe400f4f
   e:	eb 13                	jmp    0x23
  10:	e8 3a 0f 40 fe       	call   0xfe400f4f
  15:	eb 0c                	jmp    0x23
  17:	e8 33 0f 40 fe       	call   0xfe400f4f
  1c:	eb 05                	jmp    0x23
  1e:	e8 2c 0f 40 fe       	call   0xfe400f4f
  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 7e 7f fe       	call   0xfe7f7ebf
  39:	4d 8b 36             	mov    (%r14),%r14
  3c:	4c 89 f7             	mov    %r14,%rdi
  3f:	e8                   	.byte 0xe8

Crashes (274):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/30 20:19 android13-5.15-lts 61d896ee2a80 aaffb173 .config strace log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/30 00:53 android13-5.15-lts 61d896ee2a80 6ef5c1e2 .config strace log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/29 08:44 android13-5.15-lts 61d896ee2a80 19622d9d .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/29 07:48 android13-5.15-lts 61d896ee2a80 19622d9d .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/28 21:45 android13-5.15-lts 61d896ee2a80 edc8a875 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/25 09:16 android13-5.15-lts 61d896ee2a80 492bab15 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/06 14:38 android13-5.15-lts b885b84af7a2 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/06 10:13 android13-5.15-lts b885b84af7a2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/06 05:55 android13-5.15-lts b885b84af7a2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/06 04:01 android13-5.15-lts b885b84af7a2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/05 22:22 android13-5.15-lts b885b84af7a2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/05 19:28 android13-5.15-lts b885b84af7a2 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/05 17:10 android13-5.15-lts b885b84af7a2 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/05 15:04 android13-5.15-lts b885b84af7a2 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/05 12:07 android13-5.15-lts b885b84af7a2 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/05 09:02 android13-5.15-lts b885b84af7a2 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/05 05:51 android13-5.15-lts b885b84af7a2 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/05 02:40 android13-5.15-lts b885b84af7a2 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/05 01:15 android13-5.15-lts b885b84af7a2 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/04 23:48 android13-5.15-lts b885b84af7a2 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/04 19:39 android13-5.15-lts b885b84af7a2 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/04 13:42 android13-5.15-lts b885b84af7a2 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/04 11:17 android13-5.15-lts b885b84af7a2 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/04 10:11 android13-5.15-lts b885b84af7a2 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/04 07:24 android13-5.15-lts b885b84af7a2 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/04 00:44 android13-5.15-lts b885b84af7a2 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/03 23:30 android13-5.15-lts b885b84af7a2 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/03 20:31 android13-5.15-lts b885b84af7a2 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/03 20:31 android13-5.15-lts b885b84af7a2 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/03 14:51 android13-5.15-lts b885b84af7a2 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/03 05:54 android13-5.15-lts 61d896ee2a80 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/03 03:03 android13-5.15-lts 61d896ee2a80 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/08/02 12:00 android13-5.15-lts 61d896ee2a80 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/31 08:07 android13-5.15-lts 61d896ee2a80 aaffb173 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/30 15:15 android13-5.15-lts 61d896ee2a80 2377cd3d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/30 04:48 android13-5.15-lts 61d896ee2a80 6ef5c1e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/30 04:36 android13-5.15-lts 61d896ee2a80 6ef5c1e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/29 21:22 android13-5.15-lts 61d896ee2a80 6ef5c1e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/29 18:51 android13-5.15-lts 61d896ee2a80 6ef5c1e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/29 15:55 android13-5.15-lts 61d896ee2a80 6ef5c1e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/29 10:23 android13-5.15-lts 61d896ee2a80 19622d9d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/28 20:21 android13-5.15-lts 61d896ee2a80 edc8a875 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/28 14:25 android13-5.15-lts 61d896ee2a80 edc8a875 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/28 14:25 android13-5.15-lts 61d896ee2a80 edc8a875 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/28 12:31 android13-5.15-lts 61d896ee2a80 45ae1df4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/28 12:20 android13-5.15-lts 61d896ee2a80 45ae1df4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/28 11:23 android13-5.15-lts 61d896ee2a80 45ae1df4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/28 10:17 android13-5.15-lts 61d896ee2a80 45ae1df4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/28 09:10 android13-5.15-lts 61d896ee2a80 45ae1df4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/28 06:25 android13-5.15-lts 61d896ee2a80 45ae1df4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/28 05:43 android13-5.15-lts 61d896ee2a80 45ae1df4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/28 03:24 android13-5.15-lts 61d896ee2a80 45ae1df4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/27 22:58 android13-5.15-lts 61d896ee2a80 aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
2026/07/27 15:59 android13-5.15-lts 61d896ee2a80 aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in dummy_udc_start
* Struck through repros no longer work on HEAD.