Re: [syzbot] [usb?] general protection fault in vhci_hcd_probe

[Aleksandr Nogikh]

On Sun, Sep 6, 2026 at 12:38 PM Michal Pecio <michal.pecio@xxxxxxxxx> wrote:
>
> On Sat, 5 Sep 2026 13:30:01 +0200, Greg KH wrote:
> > On Sat, Sep 05, 2026 at 10:43:31AM +0200, Michal Pecio wrote:
> > > On Sat, 05 Sep 2026 01:12:27 -0700, syzbot wrote:
> > > > syzbot has found a reproducer for the following issue on:
> > > >
> > > > HEAD commit:    9d80aa4617b3 Add linux-next specific files for 20260903
> > > > git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> > > > console output: https://syzkaller.appspot.com/x/log.txt?x=10adf4f9580000
> > > > kernel config:  https://syzkaller.appspot.com/x/.config?x=bb4a32c282cc2ec7
> > > > dashboard link: https://syzkaller.appspot.com/bug?extid=7300affe388249d66dfe
> > > > compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
> > > > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=121c7215580000
> > >
> > > Who or what is coming up with these ideas and even commenting it?
> > >
> > >     // Iterate platform devices
> > >     dir = opendir("/sys/bus/platform/devices/");
> > >
> > >     while ((ent = readdir(dir)) != NULL) {
> > >
> > >         // Set driver override
> > >         snprintf(path, sizeof(path), "/sys/bus/platform/devices/%s/driver_override", ent->d_name);
> > >         fd = open(path, O_WRONLY);
> > >
> > >         // Bind to vhci_hcd
> > >         fd = open("/sys/bus/platform/drivers/vhci_hcd/bind", O_WRONLY);
> >
> > That will taint the kernel in newer releases, and syzbot has already
> > been told not to do this, it's not "valid" at all.
>
> What cought my attention is that Google apparently has some capability
> (human, machine or otherwise) to understand how this repro works, and
> yet they keep reporting this broken pattern.

As Greg pointed out, we've adjusted the fuzzer to stop using this
kernel interface, so there should be no new bugs of this type.
However, we haven't yet invalidated all such reported bugs, so some
notifications like this one may still leak. I'll look into
mass-invalidation of them all, but in the meanwhile let's close this
particular one:

#syz invalid

-- 
Aleksandr

>
> It's just waste of time, including syzbot's own time.
>
> Hence syzkaller@xxxxxxxxxxxxxxxx in Cc, wonder if there is any truth in
>
> > See https://goo.gl/tpsmEJ for more information about syzbot.
> > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx.
>
> Regards,
> Michal
>