general protection fault in dummy_queue

Status: upstream: reported on 2026/08/06 16:53
Reported-by: syzbot+2ee87a9a2213762be962@syzkaller.appspotmail.com
First crash: 15h35m, last: 15h35m
▶ ▼ Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 general protection fault in dummy_queue 2 10 3d03h 13d 0/2 upstream: reported on 2026/07/25 01:05
android-5-10 general protection fault in dummy_queue 2 11 3d21h 13d 0/2 premoderation: reported on 2026/07/24 13:21
android-6-1 general protection fault in dummy_queue 2 2 11d 13d 0/2 premoderation: reported on 2026/07/24 18:37
linux-6.1 BUG: unable to handle kernel paging request in dummy_queue 8 3 7h41m 13d 0/3 upstream: reported on 2026/07/24 22:29
android-6-12 general protection fault in dummy_queue 2 9 2d07h 10d 0/1 premoderation: reported on 2026/07/27 14:26
android-5-15 general protection fault in dummy_queue 2 7 7d00h 12d 0/2 premoderation: reported on 2026/07/25 09:31
upstream general protection fault in dummy_queue usb prio:low 10 211 6h38m 9d18h 0/29 upstream: reported on 2026/07/28 13:42

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc000000000c: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067]
CPU: 0 PID: 4747 Comm: syz.0.166 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:dummy_queue+0x1a2/0x850 drivers/usb/gadget/udc/dummy_hcd.c:714
Code: fc ff df 80 3c 08 00 74 08 4c 89 e7 e8 67 87 87 fb 4d 8b 24 24 49 83 c4 60 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 80 05 00 00 45 8b 24 24 44 89 e6 83 e6 02
RSP: 0018:ffffc9000326f9a8 EFLAGS: 00010206
RAX: 000000000000000c RBX: ffff888061614c10 RCX: dffffc0000000000
RDX: 0000000000000002 RSI: 0000000000000003 RDI: 0000000000000005
RBP: 1ffff1100c2c2980 R08: ffff88801adc000b R09: 1ffff110035b8001
R10: dffffc0000000000 R11: ffffed10035b8002 R12: 0000000000000060
R13: ffff888061614c00 R14: ffff8880231740e0 R15: ffff888023174c00
FS:  00007fd5049d56c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd5049d3fd8 CR3: 000000005fe8d000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 usb_ep_queue+0xe6/0x350 drivers/usb/gadget/udc/core.c:288
 raw_process_ep_io+0x5f7/0xc80 drivers/usb/gadget/legacy/raw_gadget.c:1061
 raw_ioctl_ep_write drivers/usb/gadget/legacy/raw_gadget.c:1101 [inline]
 raw_ioctl+0x20f7/0x3750 drivers/usb/gadget/legacy/raw_gadget.c:1274
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 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: 0033:0x7fd50679dd6b
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:00007fd5049d3f60 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000040 RCX: 00007fd50679dd6b
RDX: 00007fd5049d3fe0 RSI: 0000000040085507 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007fd506b50320 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 0000200000000300
R13: 0000000000000000 R14: 00007fd506a26090 R15: 00007ffc85bf9c58
 </TASK>
Modules linked in:
---[ end trace 55bc791c0987fbfa ]---
RIP: 0010:dummy_queue+0x1a2/0x850 drivers/usb/gadget/udc/dummy_hcd.c:714
Code: fc ff df 80 3c 08 00 74 08 4c 89 e7 e8 67 87 87 fb 4d 8b 24 24 49 83 c4 60 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 80 05 00 00 45 8b 24 24 44 89 e6 83 e6 02
RSP: 0018:ffffc9000326f9a8 EFLAGS: 00010206
RAX: 000000000000000c RBX: ffff888061614c10 RCX: dffffc0000000000
RDX: 0000000000000002 RSI: 0000000000000003 RDI: 0000000000000005
RBP: 1ffff1100c2c2980 R08: ffff88801adc000b R09: 1ffff110035b8001
R10: dffffc0000000000 R11: ffffed10035b8002 R12: 0000000000000060
R13: ffff888061614c00 R14: ffff8880231740e0 R15: ffff888023174c00
FS:  00007fd5049d56c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32714ff8 CR3: 000000005fe8d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	fc                   	cld
   1:	ff                   	lcall  (bad)
   2:	df 80 3c 08 00 74    	filds  0x7400083c(%rax)
   8:	08 4c 89 e7          	or     %cl,-0x19(%rcx,%rcx,4)
   c:	e8 67 87 87 fb       	call   0xfb878778
  11:	4d 8b 24 24          	mov    (%r12),%r12
  15:	49 83 c4 60          	add    $0x60,%r12
  19:	4c 89 e0             	mov    %r12,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	0f b6 04 08          	movzbl (%rax,%rcx,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	0f 85 80 05 00 00    	jne    0x5b6
  36:	45 8b 24 24          	mov    (%r12),%r12d
  3a:	44 89 e6             	mov    %r12d,%esi
  3d:	83 e6 02             	and    $0x2,%esi

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/06 16:52 linux-5.15.y 6e2fd6534337 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in dummy_queue
* Struck through repros no longer work on HEAD.