From: syzbot <syzbot+44835f0858f11e3e923c@syzkaller.appspotmail.com>
To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [usb?] general protection fault in uvcg_video_enable
Date: Tue, 11 Aug 2026 03:19:27 -0700 [thread overview]
Message-ID: <6a7af72f.5aeeccc9.207e63.0014.GAE@google.com> (raw)
In-Reply-To: <6a7a6961.9c11d2ce.289b96.00f6.GAE@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: d58772d8520c Merge tag 'regmap-fix-v7.2-rc7' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1434a879580000
kernel config: https://syzkaller.appspot.com/x/.config?x=d07fbc6821d72a61
dashboard link: https://syzkaller.appspot.com/bug?extid=44835f0858f11e3e923c
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17d69879580000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+44835f0858f11e3e923c@syzkaller.appspotmail.com
audit: backlog limit exceeded
configfs-gadget.g1 gadget.32: uvc: uvc_function_bind()
use of bytesused == 0 is deprecated and will be removed in the future,
use the actual size instead.
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 2 UID: 0 PID: 6048 Comm: syz-executor268 Not tainted syzkaller #0 PREEMPT(full)
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:ffffc900033a7b58 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88802e74c100 RCX: ffffffff87e608b8
RDX: 0000000000000000 RSI: ffffffff87e608c5 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: ffff88802c31e8f0 R15: ffff88802c31e840
FS: 000055555baac400(0000) GS:ffff8880d5dd7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555bab0000 CR3: 000000003df62000 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: 0033:0x7fc0f28ab40b
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:00007fffe9a50160 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fffe9a501e8 RCX: 00007fc0f28ab40b
RDX: 00007fffe9a501e0 RSI: 0000000040045612 RDI: 0000000000000003
RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000008000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fffe9a501e0 R14: 00000000c0585609 R15: 00000000c058560f
</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:ffffc900033a7b58 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88802e74c100 RCX: ffffffff87e608b8
RDX: 0000000000000000 RSI: ffffffff87e608c5 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: ffff88802c31e8f0 R15: ffff88802c31e840
FS: 000055555baac400(0000) GS:ffff8880d5cd7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055703341ef30 CR3: 000000003df62000 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
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
prev parent reply other threads:[~2026-08-11 10:19 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-11 0:14 [syzbot] [usb?] general protection fault in uvcg_video_enable syzbot
2026-08-11 10:19 ` syzbot [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=6a7af72f.5aeeccc9.207e63.0014.GAE@google.com \
--to=syzbot+44835f0858f11e3e923c@syzkaller.appspotmail.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=syzkaller-bugs@googlegroups.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox