From: bugzilla-daemon@bugzilla.kernel.org
To: linux-usb@vger.kernel.org
Subject: [Bug 212995] A possible divide by zero in qh_urb_transaction
Date: Sat, 08 May 2021 11:18:05 +0000 [thread overview]
Message-ID: <bug-212995-208809-2BOGTyS7lg@https.bugzilla.kernel.org/> (raw)
In-Reply-To: <bug-212995-208809@https.bugzilla.kernel.org/>
https://bugzilla.kernel.org/show_bug.cgi?id=212995
--- Comment #1 from Greg Kroah-Hartman (greg@kroah.com) ---
On Sat, May 08, 2021 at 11:14:25AM +0000, bugzilla-daemon@bugzilla.kernel.org
wrote:
> https://bugzilla.kernel.org/show_bug.cgi?id=212995
>
> Bug ID: 212995
> Summary: A possible divide by zero in qh_urb_transaction
> Product: Drivers
> Version: 2.5
> Kernel Version: 5.12.2
> Hardware: All
> OS: Linux
> Tree: Mainline
> Status: NEW
> Severity: normal
> Priority: P1
> Component: USB
> Assignee: drivers_usb@kernel-bugs.kernel.org
> Reporter: yguoaz@gmail.com
> Regression: No
>
> In the file drivers/usb/host/ehci-q.c, the function qh_urb_transaction has
> the
> following code (link to the code location:
>
> https://github.com/torvalds/linux/blob/dd860052c99b1e088352bdd4fb7aef46f8d2ef47/drivers/usb/host/ehci-q.c#L715):
>
> maxpacket = usb_maxpacket(urb->dev, urb->pipe, !is_input);
> ...
> if (usb_pipeout(urb->pipe) && (urb->transfer_flags & URB_ZERO_PACKET)
> && !(urb->transfer_buffer_length % maxpacket))
>
> However, the function usb_maxpacket may retun 0, leading to a possible divide
> zero problem in the remainder operation:
Please feel free to submit a patch to the developers, but first see how
it could be possible for usb_maxpacket to ever return 0 for this. Are
you sure it's not already sanitized by the time it gets here?
thanks,
greg k-h
--
You may reply to this email to add a comment.
You are receiving this mail because:
You are watching the assignee of the bug.
next prev parent reply other threads:[~2021-05-08 11:18 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-08 11:14 [Bug 212995] New: A possible divide by zero in qh_urb_transaction bugzilla-daemon
2021-05-08 11:18 ` Greg KH
2021-05-08 11:18 ` bugzilla-daemon [this message]
2021-05-08 11:37 ` [Bug 212995] " bugzilla-daemon
2021-05-08 14:36 ` bugzilla-daemon
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=bug-212995-208809-2BOGTyS7lg@https.bugzilla.kernel.org/ \
--to=bugzilla-daemon@bugzilla.kernel.org \
--cc=linux-usb@vger.kernel.org \
/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;
as well as URLs for NNTP newsgroup(s).