* [PATCH] dmaengine: pxa_dma: Prefer struct_size over open coded arithmetic
@ 2021-09-18 10:40 ` Len Baker
0 siblings, 0 replies; 6+ messages in thread
From: Len Baker @ 2021-09-18 10:40 UTC (permalink / raw)
To: Daniel Mack, Haojian Zhuang, Robert Jarzmik, Vinod Koul
Cc: Len Baker, Gustavo A. R. Silva, Kees Cook, linux-arm-kernel,
dmaengine, linux-hardening, linux-kernel
As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.
So, use the struct_size() helper to do the arithmetic instead of the
argument "size + count * size" in the kzalloc() function.
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
Signed-off-by: Len Baker <len.baker@gmx.com>
---
drivers/dma/pxa_dma.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/dma/pxa_dma.c b/drivers/dma/pxa_dma.c
index 4a2a796e348c..52d04641e361 100644
--- a/drivers/dma/pxa_dma.c
+++ b/drivers/dma/pxa_dma.c
@@ -742,8 +742,7 @@ pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc)
dma_addr_t dma;
int i;
- sw_desc = kzalloc(sizeof(*sw_desc) +
- nb_hw_desc * sizeof(struct pxad_desc_hw *),
+ sw_desc = kzalloc(struct_size(sw_desc, hw_desc, nb_hw_desc),
GFP_NOWAIT);
if (!sw_desc)
return NULL;
--
2.25.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH] dmaengine: pxa_dma: Prefer struct_size over open coded arithmetic
@ 2021-09-18 10:40 ` Len Baker
0 siblings, 0 replies; 6+ messages in thread
From: Len Baker @ 2021-09-18 10:40 UTC (permalink / raw)
To: Daniel Mack, Haojian Zhuang, Robert Jarzmik, Vinod Koul
Cc: Len Baker, Gustavo A. R. Silva, Kees Cook, linux-arm-kernel,
dmaengine, linux-hardening, linux-kernel
As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.
So, use the struct_size() helper to do the arithmetic instead of the
argument "size + count * size" in the kzalloc() function.
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
Signed-off-by: Len Baker <len.baker@gmx.com>
---
drivers/dma/pxa_dma.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/dma/pxa_dma.c b/drivers/dma/pxa_dma.c
index 4a2a796e348c..52d04641e361 100644
--- a/drivers/dma/pxa_dma.c
+++ b/drivers/dma/pxa_dma.c
@@ -742,8 +742,7 @@ pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc)
dma_addr_t dma;
int i;
- sw_desc = kzalloc(sizeof(*sw_desc) +
- nb_hw_desc * sizeof(struct pxad_desc_hw *),
+ sw_desc = kzalloc(struct_size(sw_desc, hw_desc, nb_hw_desc),
GFP_NOWAIT);
if (!sw_desc)
return NULL;
--
2.25.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] dmaengine: pxa_dma: Prefer struct_size over open coded arithmetic
2021-09-18 10:40 ` Len Baker
@ 2021-09-21 0:00 ` Gustavo A. R. Silva
-1 siblings, 0 replies; 6+ messages in thread
From: Gustavo A. R. Silva @ 2021-09-21 0:00 UTC (permalink / raw)
To: Len Baker, Daniel Mack, Haojian Zhuang, Robert Jarzmik, Vinod Koul
Cc: Gustavo A. R. Silva, Kees Cook, linux-arm-kernel, dmaengine,
linux-hardening, linux-kernel
On 9/18/21 05:40, Len Baker wrote:
> As noted in the "Deprecated Interfaces, Language Features, Attributes,
> and Conventions" documentation [1], size calculations (especially
> multiplication) should not be performed in memory allocator (or similar)
> function arguments due to the risk of them overflowing. This could lead
> to values wrapping around and a smaller allocation being made than the
> caller was expecting. Using those allocations could lead to linear
> overflows of heap memory and other misbehaviors.
>
> So, use the struct_size() helper to do the arithmetic instead of the
> argument "size + count * size" in the kzalloc() function.
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
>
> Signed-off-by: Len Baker <len.baker@gmx.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
> drivers/dma/pxa_dma.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/dma/pxa_dma.c b/drivers/dma/pxa_dma.c
> index 4a2a796e348c..52d04641e361 100644
> --- a/drivers/dma/pxa_dma.c
> +++ b/drivers/dma/pxa_dma.c
> @@ -742,8 +742,7 @@ pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc)
> dma_addr_t dma;
> int i;
>
> - sw_desc = kzalloc(sizeof(*sw_desc) +
> - nb_hw_desc * sizeof(struct pxad_desc_hw *),
> + sw_desc = kzalloc(struct_size(sw_desc, hw_desc, nb_hw_desc),
> GFP_NOWAIT);
> if (!sw_desc)
> return NULL;
> --
> 2.25.1
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] dmaengine: pxa_dma: Prefer struct_size over open coded arithmetic
@ 2021-09-21 0:00 ` Gustavo A. R. Silva
0 siblings, 0 replies; 6+ messages in thread
From: Gustavo A. R. Silva @ 2021-09-21 0:00 UTC (permalink / raw)
To: Len Baker, Daniel Mack, Haojian Zhuang, Robert Jarzmik, Vinod Koul
Cc: Gustavo A. R. Silva, Kees Cook, linux-arm-kernel, dmaengine,
linux-hardening, linux-kernel
On 9/18/21 05:40, Len Baker wrote:
> As noted in the "Deprecated Interfaces, Language Features, Attributes,
> and Conventions" documentation [1], size calculations (especially
> multiplication) should not be performed in memory allocator (or similar)
> function arguments due to the risk of them overflowing. This could lead
> to values wrapping around and a smaller allocation being made than the
> caller was expecting. Using those allocations could lead to linear
> overflows of heap memory and other misbehaviors.
>
> So, use the struct_size() helper to do the arithmetic instead of the
> argument "size + count * size" in the kzalloc() function.
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
>
> Signed-off-by: Len Baker <len.baker@gmx.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
> drivers/dma/pxa_dma.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/dma/pxa_dma.c b/drivers/dma/pxa_dma.c
> index 4a2a796e348c..52d04641e361 100644
> --- a/drivers/dma/pxa_dma.c
> +++ b/drivers/dma/pxa_dma.c
> @@ -742,8 +742,7 @@ pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc)
> dma_addr_t dma;
> int i;
>
> - sw_desc = kzalloc(sizeof(*sw_desc) +
> - nb_hw_desc * sizeof(struct pxad_desc_hw *),
> + sw_desc = kzalloc(struct_size(sw_desc, hw_desc, nb_hw_desc),
> GFP_NOWAIT);
> if (!sw_desc)
> return NULL;
> --
> 2.25.1
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] dmaengine: pxa_dma: Prefer struct_size over open coded arithmetic
2021-09-21 0:00 ` Gustavo A. R. Silva
@ 2021-10-20 23:32 ` Gustavo A. R. Silva
-1 siblings, 0 replies; 6+ messages in thread
From: Gustavo A. R. Silva @ 2021-10-20 23:32 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Len Baker, Daniel Mack, Haojian Zhuang, Robert Jarzmik,
Vinod Koul, Kees Cook, linux-arm-kernel, dmaengine,
linux-hardening, linux-kernel
On Mon, Sep 20, 2021 at 07:00:58PM -0500, Gustavo A. R. Silva wrote:
>
>
> On 9/18/21 05:40, Len Baker wrote:
> > As noted in the "Deprecated Interfaces, Language Features, Attributes,
> > and Conventions" documentation [1], size calculations (especially
> > multiplication) should not be performed in memory allocator (or similar)
> > function arguments due to the risk of them overflowing. This could lead
> > to values wrapping around and a smaller allocation being made than the
> > caller was expecting. Using those allocations could lead to linear
> > overflows of heap memory and other misbehaviors.
> >
> > So, use the struct_size() helper to do the arithmetic instead of the
> > argument "size + count * size" in the kzalloc() function.
> >
> > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
> >
> > Signed-off-by: Len Baker <len.baker@gmx.com>
>
> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
I'm taking this in my -next tree.
Thanks
--
Gustavo
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] dmaengine: pxa_dma: Prefer struct_size over open coded arithmetic
@ 2021-10-20 23:32 ` Gustavo A. R. Silva
0 siblings, 0 replies; 6+ messages in thread
From: Gustavo A. R. Silva @ 2021-10-20 23:32 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Len Baker, Daniel Mack, Haojian Zhuang, Robert Jarzmik,
Vinod Koul, Kees Cook, linux-arm-kernel, dmaengine,
linux-hardening, linux-kernel
On Mon, Sep 20, 2021 at 07:00:58PM -0500, Gustavo A. R. Silva wrote:
>
>
> On 9/18/21 05:40, Len Baker wrote:
> > As noted in the "Deprecated Interfaces, Language Features, Attributes,
> > and Conventions" documentation [1], size calculations (especially
> > multiplication) should not be performed in memory allocator (or similar)
> > function arguments due to the risk of them overflowing. This could lead
> > to values wrapping around and a smaller allocation being made than the
> > caller was expecting. Using those allocations could lead to linear
> > overflows of heap memory and other misbehaviors.
> >
> > So, use the struct_size() helper to do the arithmetic instead of the
> > argument "size + count * size" in the kzalloc() function.
> >
> > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
> >
> > Signed-off-by: Len Baker <len.baker@gmx.com>
>
> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
I'm taking this in my -next tree.
Thanks
--
Gustavo
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-10-20 23:29 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2021-09-18 10:40 [PATCH] dmaengine: pxa_dma: Prefer struct_size over open coded arithmetic Len Baker
2021-09-18 10:40 ` Len Baker
2021-09-21 0:00 ` Gustavo A. R. Silva
2021-09-21 0:00 ` Gustavo A. R. Silva
2021-10-20 23:32 ` Gustavo A. R. Silva
2021-10-20 23:32 ` Gustavo A. R. Silva
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