From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Andrey Konovalov <andreyknvl@google.com>
Cc: Valentina Manea <valentina.manea.m@gmail.com>,
Shuah Khan <shuah@kernel.org>,
Alan Stern <stern@rowland.harvard.edu>,
USB list <linux-usb@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Dmitry Vyukov <dvyukov@google.com>,
Nazime Hande Harputluoglu <handeharputlu@google.com>,
syzkaller <syzkaller@googlegroups.com>
Subject: Re: Is usb_hcd_giveback_urb() allowed in task context?
Date: Mon, 5 Oct 2020 17:18:57 +0200 [thread overview]
Message-ID: <20201005151857.GA2309511@kroah.com> (raw)
In-Reply-To: <CAAeHK+wb4k-LGTjK9F5YbJNviF_+yU+wE_=Vpo9Rn7KFN8vG6Q@mail.gmail.com>
On Mon, Oct 05, 2020 at 05:08:11PM +0200, Andrey Konovalov wrote:
> Dear USB and USB/IP maintainers,
>
> While fuzzing the USB/IP stack with syzkaller we've stumbled upon an issue.
>
> Currently kcov (the subsystem that is used for coverage collection)
> USB-related callbacks assume that usb_hcd_giveback_urb() can only be
> called from interrupt context, as indicated by the comment before the
> function definition. In the USB/IP code, however, it's called from the
> task context (see the stack trace below).
>
> Is this something that is allowed and we need to fix kcov? Or is this
> a bug in USB/IP?
It's a bug in kcov, and is not true as you have found out :)
thanks,
greg k-h
next prev parent reply other threads:[~2020-10-05 15:18 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-05 15:08 Is usb_hcd_giveback_urb() allowed in task context? Andrey Konovalov
2020-10-05 15:18 ` Greg Kroah-Hartman [this message]
2020-10-05 15:21 ` Andrey Konovalov
2020-10-05 15:25 ` Alan Stern
2020-10-05 23:38 ` Shuah Khan
2020-10-06 1:23 ` Alan Stern
2020-10-06 15:44 ` Andrey Konovalov
2020-10-05 15:22 ` Alan Stern
2020-10-05 15:28 ` Greg Kroah-Hartman
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