From: Nicolin Chen <nicolinc@nvidia.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: <iommu@lists.linux.dev>, Joerg Roedel <joro@8bytes.org>,
Kevin Tian <kevin.tian@intel.com>,
Robin Murphy <robin.murphy@arm.com>,
Will Deacon <will@kernel.org>,
Alex Williamson <alex.williamson@redhat.com>,
Joao Martins <joao.m.martins@oracle.com>,
<patches@lists.linux.dev>, <stable@vger.kernel.org>,
<syzbot+093a8a8b859472e6c257@syzkaller.appspotmail.com>,
Yishai Hadas <yishaih@nvidia.com>
Subject: Re: [PATCH rc] iommufd: Don't overflow during division for dirty tracking
Date: Wed, 8 Oct 2025 11:57:57 -0700 [thread overview]
Message-ID: <aOa0NWKpNMDSECz7@Asurada-Nvidia> (raw)
In-Reply-To: <0-v1-663679b57226+172-iommufd_dirty_div0_jgg@nvidia.com>
On Wed, Oct 08, 2025 at 03:17:18PM -0300, Jason Gunthorpe wrote:
> If pgshift is 63 then BITS_PER_TYPE(*bitmap->bitmap) * pgsize will overflow
> to 0 and this triggers divide by 0.
>
> In this case the index should just be 0, so reorganize things to divide
> by shift and avoid hitting any overflows.
>
> Cc: stable@vger.kernel.org
> Fixes: 58ccf0190d19 ("vfio: Add an IOVA bitmap support")
> Reported-by: syzbot+093a8a8b859472e6c257@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=093a8a8b859472e6c257
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
next prev parent reply other threads:[~2025-10-08 18:58 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-08 18:17 [PATCH rc] iommufd: Don't overflow during division for dirty tracking Jason Gunthorpe
2025-10-08 18:57 ` Nicolin Chen [this message]
2025-10-08 21:35 ` Joao Martins
2025-10-16 7:36 ` Tian, Kevin
2025-10-20 22:59 ` Jason Gunthorpe
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=aOa0NWKpNMDSECz7@Asurada-Nvidia \
--to=nicolinc@nvidia.com \
--cc=alex.williamson@redhat.com \
--cc=iommu@lists.linux.dev \
--cc=jgg@nvidia.com \
--cc=joao.m.martins@oracle.com \
--cc=joro@8bytes.org \
--cc=kevin.tian@intel.com \
--cc=patches@lists.linux.dev \
--cc=robin.murphy@arm.com \
--cc=stable@vger.kernel.org \
--cc=syzbot+093a8a8b859472e6c257@syzkaller.appspotmail.com \
--cc=will@kernel.org \
--cc=yishaih@nvidia.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;
as well as URLs for NNTP newsgroup(s).