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: 19d, last: 1h00m
▶ ▼ 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 332 3h46m 19d 0/3 upstream: reported C repro on 2026/07/24 22:21
android-6-1 general protection fault in dummy_udc_start 2 syz 433 1h17m 19d 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 4496 24m 15d 0/29 upstream: reported C repro on 2026/07/28 14:15
android-5-15 general protection fault in dummy_udc_start 2 syz 424 2h05m 19d 0/2 premoderation: reported syz repro on 2026/07/25 06:03
android-6-12 general protection fault in dummy_udc_start 2 syz 589 17h54m 19d 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 147 1h54m 18d 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 113 8h35m 18d 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 (661):
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
2026/08/08 21:32 android13-5.10-lts 447db0046f21 5d63f80b .config strace log report syz / log [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
2026/08/13 10:02 android13-5.10-lts e334a66065d3 359b2492 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/13 09:52 android13-5.10-lts e334a66065d3 359b2492 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/13 07:44 android13-5.10-lts e334a66065d3 359b2492 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/13 06:30 android13-5.10-lts e334a66065d3 359b2492 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/13 05:12 android13-5.10-lts e334a66065d3 359b2492 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/13 04:09 android13-5.10-lts e334a66065d3 359b2492 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/13 02:18 android13-5.10-lts e334a66065d3 359b2492 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/12 23:42 android13-5.10-lts e334a66065d3 359b2492 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/12 17:53 android13-5.10-lts 8e2d2cc88387 f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/12 16:28 android13-5.10-lts 8e2d2cc88387 f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/12 15:20 android13-5.10-lts 8e2d2cc88387 f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/12 12:43 android13-5.10-lts 8e2d2cc88387 f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/12 09:43 android13-5.10-lts 8e2d2cc88387 f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/12 08:26 android13-5.10-lts dce28bf8c73c f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/12 06:24 android13-5.10-lts dce28bf8c73c f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/12 03:08 android13-5.10-lts dce28bf8c73c f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/12 03:07 android13-5.10-lts dce28bf8c73c f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/12 01:31 android13-5.10-lts dce28bf8c73c 71790083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/12 00:10 android13-5.10-lts dce28bf8c73c 71790083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 23:01 android13-5.10-lts dce28bf8c73c 71790083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 21:49 android13-5.10-lts dce28bf8c73c 71790083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 20:23 android13-5.10-lts dce28bf8c73c 71790083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 19:06 android13-5.10-lts dce28bf8c73c 71790083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 17:46 android13-5.10-lts dce28bf8c73c 71790083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 15:23 android13-5.10-lts dce28bf8c73c 71790083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 11:58 android13-5.10-lts dce28bf8c73c 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 08:28 android13-5.10-lts dce28bf8c73c 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 07:27 android13-5.10-lts 447db0046f21 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 06:24 android13-5.10-lts 447db0046f21 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 05:25 android13-5.10-lts 447db0046f21 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 04:17 android13-5.10-lts 447db0046f21 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 03:09 android13-5.10-lts 447db0046f21 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 01:48 android13-5.10-lts 447db0046f21 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/11 00:24 android13-5.10-lts 447db0046f21 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/10 23:07 android13-5.10-lts 447db0046f21 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/10 22:27 android13-5.10-lts 447db0046f21 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/10 20:10 android13-5.10-lts 447db0046f21 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/10 18:52 android13-5.10-lts 447db0046f21 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/10 17:44 android13-5.10-lts 447db0046f21 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/10 14:52 android13-5.10-lts 447db0046f21 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/10 14:13 android13-5.10-lts 447db0046f21 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in dummy_udc_start
2026/08/10 12:58 android13-5.10-lts 447db0046f21 5d63f80b .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.