* [PATCH] drm: amdgpu: Use the correct size when allocating memory
@ 2020-08-09 20:34 Christophe JAILLET
2020-08-10 9:36 ` Christian König
2020-08-10 15:42 ` Dan Carpenter
0 siblings, 2 replies; 7+ messages in thread
From: Christophe JAILLET @ 2020-08-09 20:34 UTC (permalink / raw)
To: alexander.deucher, christian.koenig, airlied, daniel,
sumit.semwal, colton.w.lewis, Ori.Messinger, m.szyprowski,
bernard, dri-devel
Cc: amd-gfx, linux-kernel, kernel-janitors, Christophe JAILLET
When '*sgt' is allocated, we must allocated 'sizeof(**sgt)' bytes instead
of 'sizeof(*sg)'. 'sg' (i.e. struct scatterlist) is smaller than
'sgt' (i.e struct sg_table), so this could lead to memory corruption.
Fixes: f44ffd677fb3 ("drm/amdgpu: add support for exporting VRAM using DMA-buf v3")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index 134cc36e30c5..0739e259bf91 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -462,7 +462,7 @@ int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
unsigned int pages;
int i, r;
- *sgt = kmalloc(sizeof(*sg), GFP_KERNEL);
+ *sgt = kmalloc(sizeof(**sgt), GFP_KERNEL);
if (!*sgt)
return -ENOMEM;
--
2.25.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] drm: amdgpu: Use the correct size when allocating memory
2020-08-09 20:34 [PATCH] drm: amdgpu: Use the correct size when allocating memory Christophe JAILLET
@ 2020-08-10 9:36 ` Christian König
2020-08-10 15:42 ` Dan Carpenter
1 sibling, 0 replies; 7+ messages in thread
From: Christian König @ 2020-08-10 9:36 UTC (permalink / raw)
To: Christophe JAILLET, alexander.deucher, airlied, daniel,
sumit.semwal, colton.w.lewis, Ori.Messinger, m.szyprowski,
bernard, dri-devel
Cc: amd-gfx, linux-kernel, kernel-janitors
Am 09.08.20 um 22:34 schrieb Christophe JAILLET:
> When '*sgt' is allocated, we must allocated 'sizeof(**sgt)' bytes instead
> of 'sizeof(*sg)'. 'sg' (i.e. struct scatterlist) is smaller than
> 'sgt' (i.e struct sg_table), so this could lead to memory corruption.
>
> Fixes: f44ffd677fb3 ("drm/amdgpu: add support for exporting VRAM using DMA-buf v3")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Good catch, Reviewed-by: Christian König <christian.koenig@amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> index 134cc36e30c5..0739e259bf91 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> @@ -462,7 +462,7 @@ int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
> unsigned int pages;
> int i, r;
>
> - *sgt = kmalloc(sizeof(*sg), GFP_KERNEL);
> + *sgt = kmalloc(sizeof(**sgt), GFP_KERNEL);
> if (!*sgt)
> return -ENOMEM;
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] drm: amdgpu: Use the correct size when allocating memory
2020-08-09 20:34 [PATCH] drm: amdgpu: Use the correct size when allocating memory Christophe JAILLET
2020-08-10 9:36 ` Christian König
@ 2020-08-10 15:42 ` Dan Carpenter
2020-08-10 18:41 ` Marion & Christophe JAILLET
1 sibling, 1 reply; 7+ messages in thread
From: Dan Carpenter @ 2020-08-10 15:42 UTC (permalink / raw)
To: Christophe JAILLET
Cc: alexander.deucher, christian.koenig, airlied, daniel,
sumit.semwal, colton.w.lewis, Ori.Messinger, m.szyprowski,
bernard, dri-devel, amd-gfx, linux-kernel, kernel-janitors
On Sun, Aug 09, 2020 at 10:34:06PM +0200, Christophe JAILLET wrote:
> When '*sgt' is allocated, we must allocated 'sizeof(**sgt)' bytes instead
> of 'sizeof(*sg)'. 'sg' (i.e. struct scatterlist) is smaller than
> 'sgt' (i.e struct sg_table), so this could lead to memory corruption.
The sizeof(*sg) is bigger than sizeof(**sgt) so this wastes memory but
it won't lead to corruption.
11 struct scatterlist {
12 unsigned long page_link;
13 unsigned int offset;
14 unsigned int length;
15 dma_addr_t dma_address;
16 #ifdef CONFIG_NEED_SG_DMA_LENGTH
17 unsigned int dma_length;
18 #endif
19 };
42 struct sg_table {
43 struct scatterlist *sgl; /* the list */
44 unsigned int nents; /* number of mapped entries */
45 unsigned int orig_nents; /* original size of list */
46 };
regards,
dan carpenter
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] drm: amdgpu: Use the correct size when allocating memory
2020-08-10 15:42 ` Dan Carpenter
@ 2020-08-10 18:41 ` Marion & Christophe JAILLET
2020-08-10 21:15 ` Alex Deucher
2020-08-11 7:57 ` Dan Carpenter
0 siblings, 2 replies; 7+ messages in thread
From: Marion & Christophe JAILLET @ 2020-08-10 18:41 UTC (permalink / raw)
To: Dan Carpenter
Cc: alexander.deucher, christian.koenig, airlied, daniel,
sumit.semwal, colton.w.lewis, Ori.Messinger, m.szyprowski,
bernard, dri-devel, amd-gfx, linux-kernel, kernel-janitors
Le 10/08/2020 à 17:42, Dan Carpenter a écrit :
> On Sun, Aug 09, 2020 at 10:34:06PM +0200, Christophe JAILLET wrote:
>> When '*sgt' is allocated, we must allocated 'sizeof(**sgt)' bytes instead
>> of 'sizeof(*sg)'. 'sg' (i.e. struct scatterlist) is smaller than
>> 'sgt' (i.e struct sg_table), so this could lead to memory corruption.
> The sizeof(*sg) is bigger than sizeof(**sgt) so this wastes memory but
> it won't lead to corruption.
>
> 11 struct scatterlist {
> 12 unsigned long page_link;
> 13 unsigned int offset;
> 14 unsigned int length;
> 15 dma_addr_t dma_address;
> 16 #ifdef CONFIG_NEED_SG_DMA_LENGTH
> 17 unsigned int dma_length;
> 18 #endif
> 19 };
>
> 42 struct sg_table {
> 43 struct scatterlist *sgl; /* the list */
> 44 unsigned int nents; /* number of mapped entries */
> 45 unsigned int orig_nents; /* original size of list */
> 46 };
>
> regards,
> dan carpenter
My bad. I read 'struct scatterlist sgl' (without the *)
Thanks for the follow-up, Dan.
Doesn't smatch catch such mismatch?
(I've not run smatch for a while, so it is maybe reported)
Well, the proposal is still valid, even if it has less impact as
initially thought.
Thx for the review.
CJ
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] drm: amdgpu: Use the correct size when allocating memory
2020-08-10 18:41 ` Marion & Christophe JAILLET
@ 2020-08-10 21:15 ` Alex Deucher
2020-08-11 7:57 ` Dan Carpenter
1 sibling, 0 replies; 7+ messages in thread
From: Alex Deucher @ 2020-08-10 21:15 UTC (permalink / raw)
To: Marion & Christophe JAILLET
Cc: Dan Carpenter, Messinger, Ori, Dave Airlie, Bernard Zhao,
kernel-janitors, LKML, Maling list - DRI developers,
Sumit Semwal, Colton Lewis, amd-gfx list, Daniel Vetter, Deucher,
Alexander, Christian Koenig, Marek Szyprowski
Applied and updated the commit message to reflect the sizes.
Thanks!
Alex
On Mon, Aug 10, 2020 at 3:07 PM Marion & Christophe JAILLET
<christophe.jaillet@wanadoo.fr> wrote:
>
>
> Le 10/08/2020 à 17:42, Dan Carpenter a écrit :
> > On Sun, Aug 09, 2020 at 10:34:06PM +0200, Christophe JAILLET wrote:
> >> When '*sgt' is allocated, we must allocated 'sizeof(**sgt)' bytes instead
> >> of 'sizeof(*sg)'. 'sg' (i.e. struct scatterlist) is smaller than
> >> 'sgt' (i.e struct sg_table), so this could lead to memory corruption.
> > The sizeof(*sg) is bigger than sizeof(**sgt) so this wastes memory but
> > it won't lead to corruption.
> >
> > 11 struct scatterlist {
> > 12 unsigned long page_link;
> > 13 unsigned int offset;
> > 14 unsigned int length;
> > 15 dma_addr_t dma_address;
> > 16 #ifdef CONFIG_NEED_SG_DMA_LENGTH
> > 17 unsigned int dma_length;
> > 18 #endif
> > 19 };
> >
> > 42 struct sg_table {
> > 43 struct scatterlist *sgl; /* the list */
> > 44 unsigned int nents; /* number of mapped entries */
> > 45 unsigned int orig_nents; /* original size of list */
> > 46 };
> >
> > regards,
> > dan carpenter
>
>
> My bad. I read 'struct scatterlist sgl' (without the *)
> Thanks for the follow-up, Dan.
>
> Doesn't smatch catch such mismatch?
> (I've not run smatch for a while, so it is maybe reported)
>
> Well, the proposal is still valid, even if it has less impact as
> initially thought.
>
> Thx for the review.
>
> CJ
>
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] drm: amdgpu: Use the correct size when allocating memory
2020-08-10 18:41 ` Marion & Christophe JAILLET
2020-08-10 21:15 ` Alex Deucher
@ 2020-08-11 7:57 ` Dan Carpenter
2020-08-11 8:00 ` Dan Carpenter
1 sibling, 1 reply; 7+ messages in thread
From: Dan Carpenter @ 2020-08-11 7:57 UTC (permalink / raw)
To: Marion & Christophe JAILLET
Cc: alexander.deucher, christian.koenig, airlied, daniel,
sumit.semwal, colton.w.lewis, Ori.Messinger, m.szyprowski,
bernard, dri-devel, amd-gfx, linux-kernel, kernel-janitors
On Mon, Aug 10, 2020 at 08:41:14PM +0200, Marion & Christophe JAILLET wrote:
>
> Le 10/08/2020 à 17:42, Dan Carpenter a écrit :
> > On Sun, Aug 09, 2020 at 10:34:06PM +0200, Christophe JAILLET wrote:
> > > When '*sgt' is allocated, we must allocated 'sizeof(**sgt)' bytes instead
> > > of 'sizeof(*sg)'. 'sg' (i.e. struct scatterlist) is smaller than
> > > 'sgt' (i.e struct sg_table), so this could lead to memory corruption.
> > The sizeof(*sg) is bigger than sizeof(**sgt) so this wastes memory but
> > it won't lead to corruption.
> >
> > 11 struct scatterlist {
> > 12 unsigned long page_link;
> > 13 unsigned int offset;
> > 14 unsigned int length;
> > 15 dma_addr_t dma_address;
> > 16 #ifdef CONFIG_NEED_SG_DMA_LENGTH
> > 17 unsigned int dma_length;
> > 18 #endif
> > 19 };
> >
> > 42 struct sg_table {
> > 43 struct scatterlist *sgl; /* the list */
> > 44 unsigned int nents; /* number of mapped entries */
> > 45 unsigned int orig_nents; /* original size of list */
> > 46 };
> >
> > regards,
> > dan carpenter
>
>
> My bad. I read 'struct scatterlist sgl' (without the *)
> Thanks for the follow-up, Dan.
>
> Doesn't smatch catch such mismatch?
> (I've not run smatch for a while, so it is maybe reported)
That's why I was investigating it, because Smatch didn't catch it.
Smatch would have warned if it led to memory corruption. Smatch also
tries to detect struct mismatches as a separate check but for some
reason it missed it. I'm not totally sure why yet. I suspect that it's
a complicated internal reason where Sparse is the sizeof to a normal
number... It's a known issue and hard to fix.
>
> Well, the proposal is still valid, even if it has less impact as initially
> thought.
Yep.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] drm: amdgpu: Use the correct size when allocating memory
2020-08-11 7:57 ` Dan Carpenter
@ 2020-08-11 8:00 ` Dan Carpenter
0 siblings, 0 replies; 7+ messages in thread
From: Dan Carpenter @ 2020-08-11 8:00 UTC (permalink / raw)
To: Marion & Christophe JAILLET
Cc: alexander.deucher, christian.koenig, airlied, daniel,
sumit.semwal, colton.w.lewis, Ori.Messinger, m.szyprowski,
bernard, dri-devel, amd-gfx, linux-kernel, kernel-janitors
On Tue, Aug 11, 2020 at 10:57:02AM +0300, Dan Carpenter wrote:
> On Mon, Aug 10, 2020 at 08:41:14PM +0200, Marion & Christophe JAILLET wrote:
> >
> > Le 10/08/2020 à 17:42, Dan Carpenter a écrit :
> > > On Sun, Aug 09, 2020 at 10:34:06PM +0200, Christophe JAILLET wrote:
> > > > When '*sgt' is allocated, we must allocated 'sizeof(**sgt)' bytes instead
> > > > of 'sizeof(*sg)'. 'sg' (i.e. struct scatterlist) is smaller than
> > > > 'sgt' (i.e struct sg_table), so this could lead to memory corruption.
> > > The sizeof(*sg) is bigger than sizeof(**sgt) so this wastes memory but
> > > it won't lead to corruption.
> > >
> > > 11 struct scatterlist {
> > > 12 unsigned long page_link;
> > > 13 unsigned int offset;
> > > 14 unsigned int length;
> > > 15 dma_addr_t dma_address;
> > > 16 #ifdef CONFIG_NEED_SG_DMA_LENGTH
> > > 17 unsigned int dma_length;
> > > 18 #endif
> > > 19 };
> > >
> > > 42 struct sg_table {
> > > 43 struct scatterlist *sgl; /* the list */
> > > 44 unsigned int nents; /* number of mapped entries */
> > > 45 unsigned int orig_nents; /* original size of list */
> > > 46 };
> > >
> > > regards,
> > > dan carpenter
> >
> >
> > My bad. I read 'struct scatterlist sgl' (without the *)
> > Thanks for the follow-up, Dan.
> >
> > Doesn't smatch catch such mismatch?
> > (I've not run smatch for a while, so it is maybe reported)
>
> That's why I was investigating it, because Smatch didn't catch it.
>
> Smatch would have warned if it led to memory corruption. Smatch also
> tries to detect struct mismatches as a separate check but for some
> reason it missed it. I'm not totally sure why yet. I suspect that it's
> a complicated internal reason where Sparse is the sizeof to a normal
s/is/changes/
> number... It's a known issue and hard to fix.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2020-08-11 8:02 UTC | newest]
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2020-08-09 20:34 [PATCH] drm: amdgpu: Use the correct size when allocating memory Christophe JAILLET
2020-08-10 9:36 ` Christian König
2020-08-10 15:42 ` Dan Carpenter
2020-08-10 18:41 ` Marion & Christophe JAILLET
2020-08-10 21:15 ` Alex Deucher
2020-08-11 7:57 ` Dan Carpenter
2020-08-11 8:00 ` Dan Carpenter
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