* [PATCH] arm64: Do not leave an invalid area->pages pointer in dma_common_contiguous_remap()
@ 2017-04-25 18:22 Catalin Marinas
2017-04-25 18:25 ` [PATCH] drivers: dma-mapping: " Catalin Marinas
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Catalin Marinas @ 2017-04-25 18:22 UTC (permalink / raw)
To: linux-kernel
Cc: linux-arm-kernel, geert, a.hajda, robin.murphy, Laura Abbott,
Greg Kroah-Hartman
The dma_common_pages_remap() function allocates a vm_struct object and
initialises the pages pointer to value passed as argument. However, when
this function is called dma_common_contiguous_remap(), the pages array
is only temporarily allocated, being freed shortly after
dma_common_contiguous_remap() returns. Architecture code checking the
validity of an area->pages pointer would incorrectly dereference already
freed pointers. This has been exposed by the arm64 commit 44176bb38fa4
("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU").
Fixes: 513510ddba96 ("common: dma-mapping: introduce common remapping functions")
Cc: Laura Abbott <labbott@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
This is for correctness since once the arm64's mmap and get_sgtable ops
are fixed for DMA_ATTR_FORCE_CONTIGUOUS, we would no longer see the
issue. Anyway, it's better to get this fixed in case others trip over a
similar issue. I added a "Fixes" tag for completeness but I'm not sure
it's worth back-porting.
drivers/base/dma-mapping.c | 29 ++++++++++++++++++++++-------
1 file changed, 22 insertions(+), 7 deletions(-)
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index efd71cf4fdea..ab7071041141 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -277,8 +277,8 @@ EXPORT_SYMBOL(dma_common_mmap);
* remaps an array of PAGE_SIZE pages into another vm_area
* Cannot be used in non-sleeping contexts
*/
-void *dma_common_pages_remap(struct page **pages, size_t size,
- unsigned long vm_flags, pgprot_t prot,
+static struct vm_struct *__dma_common_pages_remap(struct page **pages,
+ size_t size, unsigned long vm_flags, pgprot_t prot,
const void *caller)
{
struct vm_struct *area;
@@ -287,13 +287,26 @@ void *dma_common_pages_remap(struct page **pages, size_t size,
if (!area)
return NULL;
- area->pages = pages;
-
if (map_vm_area(area, prot, pages)) {
vunmap(area->addr);
return NULL;
}
+ return area;
+}
+
+void *dma_common_pages_remap(struct page **pages, size_t size,
+ unsigned long vm_flags, pgprot_t prot,
+ const void *caller)
+{
+ struct vm_struct *area;
+
+ area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
+ if (!area)
+ return NULL;
+
+ area->pages = pages;
+
return area->addr;
}
@@ -308,7 +321,7 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
{
int i;
struct page **pages;
- void *ptr;
+ struct vm_struct *area;
unsigned long pfn;
pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
@@ -318,11 +331,13 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
for (i = 0, pfn = page_to_pfn(page); i < (size >> PAGE_SHIFT); i++)
pages[i] = pfn_to_page(pfn + i);
- ptr = dma_common_pages_remap(pages, size, vm_flags, prot, caller);
+ area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
kfree(pages);
- return ptr;
+ if (!area)
+ return NULL;
+ return area->addr;
}
/*
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] drivers: dma-mapping: Do not leave an invalid area->pages pointer in dma_common_contiguous_remap()
2017-04-25 18:22 [PATCH] arm64: Do not leave an invalid area->pages pointer in dma_common_contiguous_remap() Catalin Marinas
@ 2017-04-25 18:25 ` Catalin Marinas
2017-04-28 16:14 ` Greg Kroah-Hartman
2017-04-25 19:38 ` [PATCH] arm64: " Laura Abbott
2017-05-03 12:10 ` Robin Murphy
2 siblings, 1 reply; 6+ messages in thread
From: Catalin Marinas @ 2017-04-25 18:25 UTC (permalink / raw)
To: linux-kernel
Cc: Greg Kroah-Hartman, a.hajda, geert, Laura Abbott, robin.murphy,
linux-arm-kernel
On Tue, Apr 25, 2017 at 07:22:23PM +0100, Catalin Marinas wrote:
> The dma_common_pages_remap() function allocates a vm_struct object and
> initialises the pages pointer to value passed as argument. However, when
> this function is called dma_common_contiguous_remap(), the pages array
> is only temporarily allocated, being freed shortly after
> dma_common_contiguous_remap() returns. Architecture code checking the
> validity of an area->pages pointer would incorrectly dereference already
> freed pointers. This has been exposed by the arm64 commit 44176bb38fa4
> ("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU").
>
> Fixes: 513510ddba96 ("common: dma-mapping: introduce common remapping functions")
> Cc: Laura Abbott <labbott@redhat.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Reported-by: Andrzej Hajda <a.hajda@samsung.com>
> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Small correction on the subject, the prefix should be something like:
drivers: dma-mapping:
It's not an arm64 patch.
--
Catalin
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] arm64: Do not leave an invalid area->pages pointer in dma_common_contiguous_remap()
2017-04-25 18:22 [PATCH] arm64: Do not leave an invalid area->pages pointer in dma_common_contiguous_remap() Catalin Marinas
2017-04-25 18:25 ` [PATCH] drivers: dma-mapping: " Catalin Marinas
@ 2017-04-25 19:38 ` Laura Abbott
2017-05-03 12:10 ` Robin Murphy
2 siblings, 0 replies; 6+ messages in thread
From: Laura Abbott @ 2017-04-25 19:38 UTC (permalink / raw)
To: Catalin Marinas, linux-kernel
Cc: linux-arm-kernel, geert, a.hajda, robin.murphy, Greg Kroah-Hartman
On 04/25/2017 11:22 AM, Catalin Marinas wrote:
> The dma_common_pages_remap() function allocates a vm_struct object and
> initialises the pages pointer to value passed as argument. However, when
> this function is called dma_common_contiguous_remap(), the pages array
> is only temporarily allocated, being freed shortly after
> dma_common_contiguous_remap() returns. Architecture code checking the
> validity of an area->pages pointer would incorrectly dereference already
> freed pointers. This has been exposed by the arm64 commit 44176bb38fa4
> ("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU").
>
> Fixes: 513510ddba96 ("common: dma-mapping: introduce common remapping functions")
> Cc: Laura Abbott <labbott@redhat.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Reported-by: Andrzej Hajda <a.hajda@samsung.com>
> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Laura Abbott <labbott@redhat.com>
> ---
>
> This is for correctness since once the arm64's mmap and get_sgtable ops
> are fixed for DMA_ATTR_FORCE_CONTIGUOUS, we would no longer see the
> issue. Anyway, it's better to get this fixed in case others trip over a
> similar issue. I added a "Fixes" tag for completeness but I'm not sure
> it's worth back-porting.
>
> drivers/base/dma-mapping.c | 29 ++++++++++++++++++++++-------
> 1 file changed, 22 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
> index efd71cf4fdea..ab7071041141 100644
> --- a/drivers/base/dma-mapping.c
> +++ b/drivers/base/dma-mapping.c
> @@ -277,8 +277,8 @@ EXPORT_SYMBOL(dma_common_mmap);
> * remaps an array of PAGE_SIZE pages into another vm_area
> * Cannot be used in non-sleeping contexts
> */
> -void *dma_common_pages_remap(struct page **pages, size_t size,
> - unsigned long vm_flags, pgprot_t prot,
> +static struct vm_struct *__dma_common_pages_remap(struct page **pages,
> + size_t size, unsigned long vm_flags, pgprot_t prot,
> const void *caller)
> {
> struct vm_struct *area;
> @@ -287,13 +287,26 @@ void *dma_common_pages_remap(struct page **pages, size_t size,
> if (!area)
> return NULL;
>
> - area->pages = pages;
> -
> if (map_vm_area(area, prot, pages)) {
> vunmap(area->addr);
> return NULL;
> }
>
> + return area;
> +}
> +
> +void *dma_common_pages_remap(struct page **pages, size_t size,
> + unsigned long vm_flags, pgprot_t prot,
> + const void *caller)
> +{
> + struct vm_struct *area;
> +
> + area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
> + if (!area)
> + return NULL;
> +
> + area->pages = pages;
> +
> return area->addr;
> }
>
> @@ -308,7 +321,7 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
> {
> int i;
> struct page **pages;
> - void *ptr;
> + struct vm_struct *area;
> unsigned long pfn;
>
> pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
> @@ -318,11 +331,13 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
> for (i = 0, pfn = page_to_pfn(page); i < (size >> PAGE_SHIFT); i++)
> pages[i] = pfn_to_page(pfn + i);
>
> - ptr = dma_common_pages_remap(pages, size, vm_flags, prot, caller);
> + area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
>
> kfree(pages);
>
> - return ptr;
> + if (!area)
> + return NULL;
> + return area->addr;
> }
>
> /*
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] drivers: dma-mapping: Do not leave an invalid area->pages pointer in dma_common_contiguous_remap()
2017-04-25 18:25 ` [PATCH] drivers: dma-mapping: " Catalin Marinas
@ 2017-04-28 16:14 ` Greg Kroah-Hartman
0 siblings, 0 replies; 6+ messages in thread
From: Greg Kroah-Hartman @ 2017-04-28 16:14 UTC (permalink / raw)
To: Catalin Marinas
Cc: linux-kernel, a.hajda, geert, Laura Abbott, robin.murphy,
linux-arm-kernel
On Tue, Apr 25, 2017 at 07:25:49PM +0100, Catalin Marinas wrote:
> On Tue, Apr 25, 2017 at 07:22:23PM +0100, Catalin Marinas wrote:
> > The dma_common_pages_remap() function allocates a vm_struct object and
> > initialises the pages pointer to value passed as argument. However, when
> > this function is called dma_common_contiguous_remap(), the pages array
> > is only temporarily allocated, being freed shortly after
> > dma_common_contiguous_remap() returns. Architecture code checking the
> > validity of an area->pages pointer would incorrectly dereference already
> > freed pointers. This has been exposed by the arm64 commit 44176bb38fa4
> > ("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU").
> >
> > Fixes: 513510ddba96 ("common: dma-mapping: introduce common remapping functions")
> > Cc: Laura Abbott <labbott@redhat.com>
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Reported-by: Andrzej Hajda <a.hajda@samsung.com>
> > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
>
> Small correction on the subject, the prefix should be something like:
>
> drivers: dma-mapping:
>
> It's not an arm64 patch.
If you want to take it through your tree:
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
otherwise feel free to resend it with a fixed subject line and I can
take it :)
thanks,
greg k-h
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] arm64: Do not leave an invalid area->pages pointer in dma_common_contiguous_remap()
2017-04-25 18:22 [PATCH] arm64: Do not leave an invalid area->pages pointer in dma_common_contiguous_remap() Catalin Marinas
2017-04-25 18:25 ` [PATCH] drivers: dma-mapping: " Catalin Marinas
2017-04-25 19:38 ` [PATCH] arm64: " Laura Abbott
@ 2017-05-03 12:10 ` Robin Murphy
2017-05-03 14:12 ` Catalin Marinas
2 siblings, 1 reply; 6+ messages in thread
From: Robin Murphy @ 2017-05-03 12:10 UTC (permalink / raw)
To: Catalin Marinas, linux-kernel
Cc: linux-arm-kernel, geert, a.hajda, Laura Abbott, Greg Kroah-Hartman
On 25/04/17 19:22, Catalin Marinas wrote:
> The dma_common_pages_remap() function allocates a vm_struct object and
> initialises the pages pointer to value passed as argument. However, when
> this function is called dma_common_contiguous_remap(), the pages array
> is only temporarily allocated, being freed shortly after
> dma_common_contiguous_remap() returns. Architecture code checking the
> validity of an area->pages pointer would incorrectly dereference already
> freed pointers. This has been exposed by the arm64 commit 44176bb38fa4
> ("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU").
>
> Fixes: 513510ddba96 ("common: dma-mapping: introduce common remapping functions")
> Cc: Laura Abbott <labbott@redhat.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Reported-by: Andrzej Hajda <a.hajda@samsung.com>
> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
> ---
>
> This is for correctness since once the arm64's mmap and get_sgtable ops
> are fixed for DMA_ATTR_FORCE_CONTIGUOUS, we would no longer see the
> issue. Anyway, it's better to get this fixed in case others trip over a
> similar issue. I added a "Fixes" tag for completeness but I'm not sure
> it's worth back-porting.
>
> drivers/base/dma-mapping.c | 29 ++++++++++++++++++++++-------
> 1 file changed, 22 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
> index efd71cf4fdea..ab7071041141 100644
> --- a/drivers/base/dma-mapping.c
> +++ b/drivers/base/dma-mapping.c
> @@ -277,8 +277,8 @@ EXPORT_SYMBOL(dma_common_mmap);
> * remaps an array of PAGE_SIZE pages into another vm_area
> * Cannot be used in non-sleeping contexts
> */
Nit: the above comment ends up in the wrong place now (it should still
belong to dma_common_pages_remap()).
Otherwise,
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
> -void *dma_common_pages_remap(struct page **pages, size_t size,
> - unsigned long vm_flags, pgprot_t prot,
> +static struct vm_struct *__dma_common_pages_remap(struct page **pages,
> + size_t size, unsigned long vm_flags, pgprot_t prot,
> const void *caller)
> {
> struct vm_struct *area;
> @@ -287,13 +287,26 @@ void *dma_common_pages_remap(struct page **pages, size_t size,
> if (!area)
> return NULL;
>
> - area->pages = pages;
> -
> if (map_vm_area(area, prot, pages)) {
> vunmap(area->addr);
> return NULL;
> }
>
> + return area;
> +}
> +
> +void *dma_common_pages_remap(struct page **pages, size_t size,
> + unsigned long vm_flags, pgprot_t prot,
> + const void *caller)
> +{
> + struct vm_struct *area;
> +
> + area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
> + if (!area)
> + return NULL;
> +
> + area->pages = pages;
> +
> return area->addr;
> }
>
> @@ -308,7 +321,7 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
> {
> int i;
> struct page **pages;
> - void *ptr;
> + struct vm_struct *area;
> unsigned long pfn;
>
> pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
> @@ -318,11 +331,13 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
> for (i = 0, pfn = page_to_pfn(page); i < (size >> PAGE_SHIFT); i++)
> pages[i] = pfn_to_page(pfn + i);
>
> - ptr = dma_common_pages_remap(pages, size, vm_flags, prot, caller);
> + area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
>
> kfree(pages);
>
> - return ptr;
> + if (!area)
> + return NULL;
> + return area->addr;
> }
>
> /*
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] arm64: Do not leave an invalid area->pages pointer in dma_common_contiguous_remap()
2017-05-03 12:10 ` Robin Murphy
@ 2017-05-03 14:12 ` Catalin Marinas
0 siblings, 0 replies; 6+ messages in thread
From: Catalin Marinas @ 2017-05-03 14:12 UTC (permalink / raw)
To: Robin Murphy
Cc: linux-kernel, a.hajda, Laura Abbott, geert, linux-arm-kernel,
Greg Kroah-Hartman
On Wed, May 03, 2017 at 01:10:26PM +0100, Robin Murphy wrote:
> On 25/04/17 19:22, Catalin Marinas wrote:
> > The dma_common_pages_remap() function allocates a vm_struct object and
> > initialises the pages pointer to value passed as argument. However, when
> > this function is called dma_common_contiguous_remap(), the pages array
> > is only temporarily allocated, being freed shortly after
> > dma_common_contiguous_remap() returns. Architecture code checking the
> > validity of an area->pages pointer would incorrectly dereference already
> > freed pointers. This has been exposed by the arm64 commit 44176bb38fa4
> > ("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU").
> >
> > Fixes: 513510ddba96 ("common: dma-mapping: introduce common remapping functions")
> > Cc: Laura Abbott <labbott@redhat.com>
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Reported-by: Andrzej Hajda <a.hajda@samsung.com>
> > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
> > ---
> >
> > This is for correctness since once the arm64's mmap and get_sgtable ops
> > are fixed for DMA_ATTR_FORCE_CONTIGUOUS, we would no longer see the
> > issue. Anyway, it's better to get this fixed in case others trip over a
> > similar issue. I added a "Fixes" tag for completeness but I'm not sure
> > it's worth back-porting.
> >
> > drivers/base/dma-mapping.c | 29 ++++++++++++++++++++++-------
> > 1 file changed, 22 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
> > index efd71cf4fdea..ab7071041141 100644
> > --- a/drivers/base/dma-mapping.c
> > +++ b/drivers/base/dma-mapping.c
> > @@ -277,8 +277,8 @@ EXPORT_SYMBOL(dma_common_mmap);
> > * remaps an array of PAGE_SIZE pages into another vm_area
> > * Cannot be used in non-sleeping contexts
> > */
>
> Nit: the above comment ends up in the wrong place now (it should still
> belong to dma_common_pages_remap()).
Good point, thanks. I'll send a v2 to Greg as we don't really have a
dependency on this on arm64 (once the DMA_ATTR_FORCE_CONTIGUOUS patch is
fixed or reverted).
--
Catalin
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-05-03 14:12 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2017-04-25 18:22 [PATCH] arm64: Do not leave an invalid area->pages pointer in dma_common_contiguous_remap() Catalin Marinas
2017-04-25 18:25 ` [PATCH] drivers: dma-mapping: " Catalin Marinas
2017-04-28 16:14 ` Greg Kroah-Hartman
2017-04-25 19:38 ` [PATCH] arm64: " Laura Abbott
2017-05-03 12:10 ` Robin Murphy
2017-05-03 14:12 ` Catalin Marinas
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