[moderation] [usb?] general protection fault in uvcg_video_enable

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Aug 9, 2026, 8:12:33 PM (9 hours ago) Aug 9
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Hello,

syzbot found the following issue on:

HEAD commit: 562bfb501c54 Merge tag 'integrity-v7.2-rc7' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14467649580000
kernel config: https://syzkaller.appspot.com/x/.config?x=145fa60d73086782
dashboard link: https://syzkaller.appspot.com/bug?extid=05b327eecd6195b8b310
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
CC: [gre...@linuxfoundation.org linux-...@vger.kernel.org linu...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-562bfb50.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9cbf6ef0490e/vmlinux-562bfb50.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7ee52864c79a/bzImage-562bfb50.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+05b327...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 3 UID: 0 PID: 28280 Comm: syz.9.8123 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:usb_endpoint_xfer_isoc include/uapi/linux/usb/ch9.h:571 [inline]
RIP: 0010:uvc_video_prep_requests drivers/usb/gadget/function/uvc_video.c:508 [inline]
RIP: 0010:uvc_video_alloc_requests drivers/usb/gadget/function/uvc_video.c:559 [inline]
RIP: 0010:uvcg_video_enable+0x12d/0xf80 drivers/usb/gadget/function/uvc_video.c:784
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b7 0d 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 18 48 8d 7d 03 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 e5 0d 00 00
RSP: 0018:ffffc900049bfb58 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88802e370100 RCX: ffffc900269c2000
RDX: 0000000000000000 RSI: ffffffff87e536f5 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: ffff888038c6a8f0 R15: ffff888038c6a840
FS: 00007f57b8fed6c0(0000) GS:ffff8880d60d8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f57b8187640 CR3: 0000000057c2a000 CR4: 0000000000352ef0
Call Trace:
<TASK>
uvc_v4l2_streamon+0x9f/0x130 drivers/usb/gadget/function/uvc_v4l2.c:531
__video_do_ioctl+0xb2a/0xdf0 drivers/media/v4l2-core/v4l2-ioctl.c:3133
video_usercopy+0x47a/0x1730 drivers/media/v4l2-core/v4l2-ioctl.c:3475
v4l2_ioctl+0x1bd/0x250 drivers/media/v4l2-core/v4l2-dev.c:366
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f57b819e019
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f57b8fed028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f57b8425fa0 RCX: 00007f57b819e019
RDX: 0000200000000080 RSI: 0000000040045612 RDI: 0000000000000003
RBP: 00007f57b823500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f57b8426038 R14: 00007f57b8425fa0 R15: 00007ffc338da308
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:usb_endpoint_xfer_isoc include/uapi/linux/usb/ch9.h:571 [inline]
RIP: 0010:uvc_video_prep_requests drivers/usb/gadget/function/uvc_video.c:508 [inline]
RIP: 0010:uvc_video_alloc_requests drivers/usb/gadget/function/uvc_video.c:559 [inline]
RIP: 0010:uvcg_video_enable+0x12d/0xf80 drivers/usb/gadget/function/uvc_video.c:784
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b7 0d 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 18 48 8d 7d 03 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 e5 0d 00 00
RSP: 0018:ffffc900049bfb58 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88802e370100 RCX: ffffc900269c2000
RDX: 0000000000000000 RSI: ffffffff87e536f5 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: ffff888038c6a8f0 R15: ffff888038c6a840
FS: 00007f57b8fed6c0(0000) GS:ffff8880d5fd8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f57b81eb700 CR3: 0000000057c2a000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: 48 89 fa mov %rdi,%rdx
3: 48 c1 ea 03 shr $0x3,%rdx
7: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
b: 0f 85 b7 0d 00 00 jne 0xdc8
11: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
18: fc ff df
1b: 48 8b 6b 18 mov 0x18(%rbx),%rbp
1f: 48 8d 7d 03 lea 0x3(%rbp),%rdi
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction
2e: 48 89 fa mov %rdi,%rdx
31: 83 e2 07 and $0x7,%edx
34: 38 d0 cmp %dl,%al
36: 7f 08 jg 0x40
38: 84 c0 test %al,%al
3a: 0f 85 e5 0d 00 00 jne 0xe25


---
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