From: Joerg Roedel <joro@8bytes.org>
To: Joerg Roedel <joro@8bytes.org>
Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
Joerg Roedel <jroedel@suse.de>,
Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Subject: [PATCH] iommu: Don't take group reference in iommu_alloc_default_domain()
Date: Mon, 25 May 2020 15:01:22 +0200 [thread overview]
Message-ID: <20200525130122.380-1-joro@8bytes.org> (raw)
From: Joerg Roedel <jroedel@suse.de>
The iommu_alloc_default_domain() function takes a reference to an IOMMU
group without releasing it. This causes the group to never be released,
with undefined side effects.
The function has only one call-site, which takes a group reference on
its own, so to fix this leak, do not take another reference in
iommu_alloc_default_domain() and pass the group as a function parameter
instead.
Reference: https://lore.kernel.org/lkml/20200522130145.30067-1-saiprakash.ranjan@codeaurora.org/
Reported-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Cc: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Fixes: 6e1aa2049154 ("iommu: Move default domain allocation to iommu_probe_device()")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/iommu.c | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 374b34fd6fac..bf20674769e0 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -80,7 +80,8 @@ static bool iommu_cmd_line_dma_api(void)
return !!(iommu_cmd_line & IOMMU_CMD_LINE_DMA_API);
}
-static int iommu_alloc_default_domain(struct device *dev);
+static int iommu_alloc_default_domain(struct iommu_group *group,
+ struct device *dev);
static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
unsigned type);
static int __iommu_attach_device(struct iommu_domain *domain,
@@ -251,17 +252,17 @@ int iommu_probe_device(struct device *dev)
if (ret)
goto err_out;
+ group = iommu_group_get(dev);
+ if (!group)
+ goto err_release;
+
/*
* Try to allocate a default domain - needs support from the
* IOMMU driver. There are still some drivers which don't
* support default domains, so the return value is not yet
* checked.
*/
- iommu_alloc_default_domain(dev);
-
- group = iommu_group_get(dev);
- if (!group)
- goto err_release;
+ iommu_alloc_default_domain(group, dev);
if (group->default_domain)
ret = __iommu_attach_device(group->default_domain, dev);
@@ -1478,15 +1479,11 @@ static int iommu_group_alloc_default_domain(struct bus_type *bus,
return 0;
}
-static int iommu_alloc_default_domain(struct device *dev)
+static int iommu_alloc_default_domain(struct iommu_group *group,
+ struct device *dev)
{
- struct iommu_group *group;
unsigned int type;
- group = iommu_group_get(dev);
- if (!group)
- return -ENODEV;
-
if (group->default_domain)
return 0;
--
2.26.2
next reply other threads:[~2020-05-25 13:01 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-25 13:01 Joerg Roedel [this message]
2020-05-25 13:24 ` [PATCH] iommu: Don't take group reference in iommu_alloc_default_domain() Sai Prakash Ranjan
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