From: Ashish Mhetre <amhetre@nvidia.com>
To: <amhetre@nvidia.com>, <robin.murphy@arm.com>, <will@kernel.org>,
<vdumpa@nvidia.com>
Cc: <iommu@lists.linux-foundation.org>,
<linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>
Subject: [Patch V3 1/2] iommu: Fix race condition during default domain allocation
Date: Tue, 10 Aug 2021 10:14:00 +0530 [thread overview]
Message-ID: <1628570641-9127-2-git-send-email-amhetre@nvidia.com> (raw)
In-Reply-To: <1628570641-9127-1-git-send-email-amhetre@nvidia.com>
When two devices with same SID are getting probed concurrently through
iommu_probe_device(), the iommu_domain sometimes is getting allocated more
than once as call to iommu_alloc_default_domain() is not protected for
concurrency. Furthermore, it leads to each device holding a different
iommu_domain pointer, separate IOVA space and only one of the devices'
domain is used for translations from IOMMU. This causes accesses from other
device to fault or see incorrect translations.
Fix this by protecting iommu_alloc_default_domain() call with group->mutex
and let all devices with same SID share same iommu_domain.
Signed-off-by: Ashish Mhetre <amhetre@nvidia.com>
---
drivers/iommu/iommu.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 5419c4b..80c5a1c 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -273,7 +273,9 @@ int iommu_probe_device(struct device *dev)
* support default domains, so the return value is not yet
* checked.
*/
+ mutex_lock(&group->mutex);
iommu_alloc_default_domain(group, dev);
+ mutex_unlock(&group->mutex);
if (group->default_domain) {
ret = __iommu_attach_device(group->default_domain, dev);
--
2.7.4
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-08-10 4:47 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-10 4:43 [Patch V3 0/2] iommu/arm-smmu: Fix races in iommu domain/group creation Ashish Mhetre
2021-08-10 4:44 ` Ashish Mhetre [this message]
2021-08-10 4:44 ` [Patch V3 2/2] iommu/arm-smmu: Fix race condition during iommu_group creation Ashish Mhetre
2021-08-10 20:25 ` [Patch V3 0/2] iommu/arm-smmu: Fix races in iommu domain/group creation Will Deacon
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=1628570641-9127-2-git-send-email-amhetre@nvidia.com \
--to=amhetre@nvidia.com \
--cc=iommu@lists.linux-foundation.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=robin.murphy@arm.com \
--cc=vdumpa@nvidia.com \
--cc=will@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).