From: Linus Torvalds <torvalds@linux-foundation.org>
To: Robin Murphy <robin.murphy@arm.com>
Cc: "Oleksandr Natalenko" <oleksandr@natalenko.name>,
"Halil Pasic" <pasic@linux.ibm.com>,
"Christoph Hellwig" <hch@lst.de>,
"Marek Szyprowski" <m.szyprowski@samsung.com>,
"Toke Høiland-Jørgensen" <toke@toke.dk>,
"Kalle Valo" <kvalo@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
"Jakub Kicinski" <kuba@kernel.org>,
"Paolo Abeni" <pabeni@redhat.com>,
"Olha Cherevyk" <olha.cherevyk@gmail.com>,
iommu <iommu@lists.linux-foundation.org>,
linux-wireless <linux-wireless@vger.kernel.org>,
Netdev <netdev@vger.kernel.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
stable <stable@vger.kernel.org>
Subject: Re: [REGRESSION] Recent swiotlb DMA_FROM_DEVICE fixes break ath9k-based AP
Date: Wed, 23 Mar 2022 12:16:33 -0700 [thread overview]
Message-ID: <CAHk-=wip7TCD_+2STTepuEZvGMg6wcz+o=kyFUvHjuKziTMixw@mail.gmail.com> (raw)
In-Reply-To: <27b5a287-7a33-9a8b-ad6d-04746735fb0c@arm.com>
On Wed, Mar 23, 2022 at 12:06 PM Robin Murphy <robin.murphy@arm.com> wrote:
>
> On 2022-03-23 17:27, Linus Torvalds wrote:
> >
> > I'm assuming that the ath9k issue is that it gives DMA mapping a big
> > enough area to handle any possible packet size, and just expects -
> > quite reasonably - smaller packets to only fill the part they need.
> >
> > Which that "info leak" patch obviously breaks entirely.
>
> Except that's the exact case which the new patch is addressing
Not "addressing". Breaking.
Which is why it will almost certainly get reverted.
Not doing DMA to the whole area seems to be quite the sane thing to do
for things like network packets, and overwriting the part that didn't
get DMA'd with zeroes seems to be exactly the wrong thing here.
So the SG_IO - and other random untrusted block command sources - data
leak will almost certainly have to be addressed differently. Possibly
by simply allocating the area with GFP_ZERO to begin with.
Linus
WARNING: multiple messages have this Message-ID (diff)
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Robin Murphy <robin.murphy@arm.com>
Cc: "Toke Høiland-Jørgensen" <toke@toke.dk>,
Netdev <netdev@vger.kernel.org>, "Kalle Valo" <kvalo@kernel.org>,
linux-wireless <linux-wireless@vger.kernel.org>,
"Oleksandr Natalenko" <oleksandr@natalenko.name>,
stable <stable@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>,
"Halil Pasic" <pasic@linux.ibm.com>,
iommu <iommu@lists.linux-foundation.org>,
"Olha Cherevyk" <olha.cherevyk@gmail.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Jakub Kicinski" <kuba@kernel.org>,
"Paolo Abeni" <pabeni@redhat.com>,
"Christoph Hellwig" <hch@lst.de>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>
Subject: Re: [REGRESSION] Recent swiotlb DMA_FROM_DEVICE fixes break ath9k-based AP
Date: Wed, 23 Mar 2022 12:16:33 -0700 [thread overview]
Message-ID: <CAHk-=wip7TCD_+2STTepuEZvGMg6wcz+o=kyFUvHjuKziTMixw@mail.gmail.com> (raw)
In-Reply-To: <27b5a287-7a33-9a8b-ad6d-04746735fb0c@arm.com>
On Wed, Mar 23, 2022 at 12:06 PM Robin Murphy <robin.murphy@arm.com> wrote:
>
> On 2022-03-23 17:27, Linus Torvalds wrote:
> >
> > I'm assuming that the ath9k issue is that it gives DMA mapping a big
> > enough area to handle any possible packet size, and just expects -
> > quite reasonably - smaller packets to only fill the part they need.
> >
> > Which that "info leak" patch obviously breaks entirely.
>
> Except that's the exact case which the new patch is addressing
Not "addressing". Breaking.
Which is why it will almost certainly get reverted.
Not doing DMA to the whole area seems to be quite the sane thing to do
for things like network packets, and overwriting the part that didn't
get DMA'd with zeroes seems to be exactly the wrong thing here.
So the SG_IO - and other random untrusted block command sources - data
leak will almost certainly have to be addressed differently. Possibly
by simply allocating the area with GFP_ZERO to begin with.
Linus
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2022-03-23 19:16 UTC|newest]
Thread overview: 139+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-23 7:19 [REGRESSION] Recent swiotlb DMA_FROM_DEVICE fixes break ath9k-based AP Oleksandr Natalenko
2022-03-23 7:19 ` Oleksandr Natalenko via iommu
2022-03-23 7:28 ` Kalle Valo
2022-03-23 7:28 ` Kalle Valo
2022-03-23 17:27 ` Linus Torvalds
2022-03-23 17:27 ` Linus Torvalds
2022-03-23 19:06 ` Robin Murphy
2022-03-23 19:06 ` Robin Murphy
2022-03-23 19:16 ` Linus Torvalds [this message]
2022-03-23 19:16 ` Linus Torvalds
2022-03-23 20:54 ` Robin Murphy
2022-03-23 20:54 ` Robin Murphy
2022-03-24 5:57 ` Christoph Hellwig
2022-03-24 5:57 ` Christoph Hellwig
2022-03-24 10:25 ` Oleksandr Natalenko
2022-03-24 10:25 ` Oleksandr Natalenko via iommu
2022-03-24 11:05 ` Robin Murphy
2022-03-24 11:05 ` Robin Murphy
2022-03-24 14:27 ` Toke Høiland-Jørgensen
2022-03-24 14:27 ` Toke Høiland-Jørgensen via iommu
2022-03-24 16:29 ` Maxime Bizon
2022-03-24 16:29 ` Maxime Bizon
2022-03-24 16:31 ` Christoph Hellwig
2022-03-24 16:31 ` Christoph Hellwig
2022-03-24 16:52 ` Robin Murphy
2022-03-24 16:52 ` Robin Murphy
2022-03-24 17:07 ` Toke Høiland-Jørgensen
2022-03-24 17:07 ` Toke Høiland-Jørgensen via iommu
2022-03-24 19:26 ` Linus Torvalds
2022-03-24 19:26 ` Linus Torvalds
2022-03-24 21:14 ` Toke Høiland-Jørgensen
2022-03-24 21:14 ` Toke Høiland-Jørgensen via iommu
2022-03-25 10:25 ` Maxime Bizon
2022-03-25 10:25 ` Maxime Bizon
2022-03-25 11:27 ` Robin Murphy
2022-03-25 11:27 ` Robin Murphy
2022-03-25 23:38 ` Halil Pasic
2022-03-25 23:38 ` Halil Pasic
2022-03-26 16:05 ` Toke Høiland-Jørgensen
2022-03-26 16:05 ` Toke Høiland-Jørgensen via iommu
2022-03-26 18:38 ` Linus Torvalds
2022-03-26 18:38 ` Linus Torvalds
2022-03-26 22:38 ` David Laight
2022-03-26 22:38 ` David Laight
2022-03-26 22:41 ` Linus Torvalds
2022-03-26 22:41 ` Linus Torvalds
2022-03-25 16:25 ` Toke Høiland-Jørgensen
2022-03-25 16:25 ` Toke Høiland-Jørgensen via iommu
2022-03-25 16:45 ` Robin Murphy
2022-03-25 16:45 ` Robin Murphy
2022-03-25 18:13 ` Toke Høiland-Jørgensen via iommu
2022-03-25 18:13 ` Toke Høiland-Jørgensen
2022-03-25 18:30 ` Linus Torvalds
2022-03-25 18:30 ` Linus Torvalds
2022-03-25 19:14 ` Robin Murphy
2022-03-25 19:14 ` Robin Murphy
2022-03-25 19:21 ` Linus Torvalds
2022-03-25 19:21 ` Linus Torvalds
2022-03-25 19:26 ` Oleksandr Natalenko via iommu
2022-03-25 19:26 ` Oleksandr Natalenko
2022-03-25 19:27 ` Linus Torvalds
2022-03-25 19:27 ` Linus Torvalds
2022-03-25 19:35 ` Oleksandr Natalenko via iommu
2022-03-25 19:35 ` Oleksandr Natalenko
2022-03-25 20:37 ` Johannes Berg
2022-03-25 20:37 ` Johannes Berg
2022-03-25 20:47 ` Linus Torvalds
2022-03-25 20:47 ` Linus Torvalds
2022-03-25 21:13 ` Johannes Berg
2022-03-25 21:13 ` Johannes Berg
2022-03-25 21:40 ` David Laight
2022-03-25 21:40 ` David Laight
2022-03-25 21:56 ` Linus Torvalds
2022-03-25 21:56 ` Linus Torvalds
2022-03-25 22:41 ` David Laight
2022-03-25 22:41 ` David Laight
2022-03-27 3:15 ` Halil Pasic
2022-03-27 3:15 ` Halil Pasic
2022-03-28 9:48 ` Johannes Berg
2022-03-28 9:48 ` Johannes Berg
2022-03-28 9:50 ` Johannes Berg
2022-03-28 9:50 ` Johannes Berg
2022-03-28 9:57 ` Johannes Berg
2022-03-28 9:57 ` Johannes Berg
2022-03-27 3:48 ` Halil Pasic
2022-03-27 3:48 ` Halil Pasic
2022-03-27 5:06 ` Linus Torvalds
2022-03-27 5:06 ` Linus Torvalds
2022-03-27 5:21 ` Linus Torvalds
2022-03-27 5:21 ` Linus Torvalds
2022-03-27 15:24 ` David Laight
2022-03-27 15:24 ` David Laight
2022-03-27 19:23 ` Linus Torvalds
2022-03-27 19:23 ` Linus Torvalds
2022-03-27 20:04 ` Linus Torvalds
2022-03-27 20:04 ` Linus Torvalds
2022-03-27 23:52 ` Halil Pasic
2022-03-27 23:52 ` Halil Pasic
2022-03-28 0:30 ` Linus Torvalds
2022-03-28 0:30 ` Linus Torvalds
2022-03-28 12:02 ` Halil Pasic
2022-03-28 12:02 ` Halil Pasic
2022-03-27 23:37 ` Halil Pasic
2022-03-27 23:37 ` Halil Pasic
2022-03-28 0:37 ` Linus Torvalds
2022-03-28 0:37 ` Linus Torvalds
2022-03-25 7:12 ` Oleksandr Natalenko
2022-03-25 7:12 ` Oleksandr Natalenko via iommu
2022-03-25 9:21 ` Thorsten Leemhuis
2022-03-25 9:21 ` Thorsten Leemhuis
2022-03-24 18:31 ` Halil Pasic
2022-03-24 18:31 ` Halil Pasic
2022-03-25 16:31 ` Christoph Hellwig
2022-03-25 16:31 ` Christoph Hellwig
2022-03-24 18:02 ` Halil Pasic
2022-03-24 18:02 ` Halil Pasic
2022-03-25 15:25 ` Halil Pasic
2022-03-25 15:25 ` Halil Pasic
2022-03-25 16:23 ` Robin Murphy
2022-03-25 16:23 ` Robin Murphy
2022-03-25 16:32 ` Christoph Hellwig
2022-03-25 16:32 ` Christoph Hellwig
2022-03-25 18:15 ` Toke Høiland-Jørgensen via iommu
2022-03-25 18:15 ` Toke Høiland-Jørgensen
2022-03-25 18:42 ` Robin Murphy
2022-03-25 18:42 ` Robin Murphy
2022-03-25 18:46 ` Linus Torvalds
2022-03-25 18:46 ` Linus Torvalds
2022-03-28 6:37 ` Christoph Hellwig
2022-03-28 6:37 ` Christoph Hellwig
2022-03-28 8:15 ` David Laight
2022-03-28 8:15 ` David Laight
2022-03-30 12:11 ` Halil Pasic
2022-03-30 12:11 ` Halil Pasic
2022-03-24 8:55 ` Oleksandr Natalenko
2022-03-24 8:55 ` Oleksandr Natalenko via iommu
2022-03-24 12:32 ` [REGRESSION] Recent swiotlb DMA_FROM_DEVICE fixes break ath9k-based AP #forregzbot Thorsten Leemhuis
2022-03-25 9:24 ` Thorsten Leemhuis
2022-03-27 9:00 ` Thorsten Leemhuis
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='CAHk-=wip7TCD_+2STTepuEZvGMg6wcz+o=kyFUvHjuKziTMixw@mail.gmail.com' \
--to=torvalds@linux-foundation.org \
--cc=davem@davemloft.net \
--cc=gregkh@linuxfoundation.org \
--cc=hch@lst.de \
--cc=iommu@lists.linux-foundation.org \
--cc=kuba@kernel.org \
--cc=kvalo@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-wireless@vger.kernel.org \
--cc=m.szyprowski@samsung.com \
--cc=netdev@vger.kernel.org \
--cc=oleksandr@natalenko.name \
--cc=olha.cherevyk@gmail.com \
--cc=pabeni@redhat.com \
--cc=pasic@linux.ibm.com \
--cc=robin.murphy@arm.com \
--cc=stable@vger.kernel.org \
--cc=toke@toke.dk \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.