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* [PATCH][drm-next] drm/amd/display: fix a potential null pointer dereference
@ 2019-08-16 22:10 Colin King
  2019-08-17  6:51 ` Dan Carpenter
  2019-08-22 19:21 ` Harry Wentland
  0 siblings, 2 replies; 4+ messages in thread
From: Colin King @ 2019-08-16 22:10 UTC (permalink / raw)
  To: Harry Wentland, Leo Li, Alex Deucher, Christian König,
	David Zhou, David Airlie, Daniel Vetter, amd-gfx, dri-devel
  Cc: kernel-janitors, linux-kernel

From: Colin Ian King <colin.king@canonical.com>

Currently the pointer init_data is dereferenced on the assignment
of fw_info before init_data is sanity checked to see if it is null.
Fix te potential null pointer dereference on init_data by only
performing dereference after it is null checked.

Addresses-Coverity: ("Dereference before null check")
Fixes: 9adc8050bf3c ("drm/amd/display: make firmware info only load once during dc_bios create")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
index bee81bf288be..926954c804a6 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
@@ -1235,7 +1235,7 @@ static bool calc_pll_max_vco_construct(
 			struct calc_pll_clock_source_init_data *init_data)
 {
 	uint32_t i;
-	struct dc_firmware_info *fw_info = &init_data->bp->fw_info;
+	struct dc_firmware_info *fw_info;
 	if (calc_pll_cs == NULL ||
 			init_data == NULL ||
 			init_data->bp == NULL)
@@ -1244,6 +1244,7 @@ static bool calc_pll_max_vco_construct(
 	if (init_data->bp->fw_info_valid)
 		return false;
 
+	fw_info = &init_data->bp->fw_info;
 	calc_pll_cs->ctx = init_data->ctx;
 	calc_pll_cs->ref_freq_khz = fw_info->pll_info.crystal_frequency;
 	calc_pll_cs->min_vco_khz =
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH][drm-next] drm/amd/display: fix a potential null pointer dereference
  2019-08-16 22:10 [PATCH][drm-next] drm/amd/display: fix a potential null pointer dereference Colin King
@ 2019-08-17  6:51 ` Dan Carpenter
  2019-08-22 19:21 ` Harry Wentland
  1 sibling, 0 replies; 4+ messages in thread
From: Dan Carpenter @ 2019-08-17  6:51 UTC (permalink / raw)
  To: Colin King
  Cc: Harry Wentland, Leo Li, Alex Deucher, Christian König,
	David Zhou, David Airlie, Daniel Vetter, amd-gfx, dri-devel,
	kernel-janitors, linux-kernel

On Fri, Aug 16, 2019 at 11:10:11PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> Currently the pointer init_data is dereferenced on the assignment
> of fw_info before init_data is sanity checked to see if it is null.
> Fix te potential null pointer dereference on init_data by only
> performing dereference after it is null checked.
> 
> Addresses-Coverity: ("Dereference before null check")
> Fixes: 9adc8050bf3c ("drm/amd/display: make firmware info only load once during dc_bios create")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
> index bee81bf288be..926954c804a6 100644
> --- a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
> +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
> @@ -1235,7 +1235,7 @@ static bool calc_pll_max_vco_construct(
>  			struct calc_pll_clock_source_init_data *init_data)
>  {
>  	uint32_t i;
> -	struct dc_firmware_info *fw_info = &init_data->bp->fw_info;
> +	struct dc_firmware_info *fw_info;
>  	if (calc_pll_cs == NULL ||
>  			init_data == NULL ||
>  			init_data->bp == NULL)

init_data can't be NULL.  I'm mostly pointing this out because that NULL
check is written so higgledy-piggledy.  At first I thought this was
staging code so I was planning to ignore the patch.  :P

regards,
dan carpenter


^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH][drm-next] drm/amd/display: fix a potential null pointer dereference
  2019-08-16 22:10 [PATCH][drm-next] drm/amd/display: fix a potential null pointer dereference Colin King
  2019-08-17  6:51 ` Dan Carpenter
@ 2019-08-22 19:21 ` Harry Wentland
  2019-08-22 20:55   ` Alex Deucher
  1 sibling, 1 reply; 4+ messages in thread
From: Harry Wentland @ 2019-08-22 19:21 UTC (permalink / raw)
  To: Colin King, Wentland, Harry, Li, Sun peng (Leo),
	Deucher, Alexander, Koenig, Christian, Zhou, David(ChunMing),
	David Airlie, Daniel Vetter, amd-gfx, dri-devel
  Cc: kernel-janitors, linux-kernel

On 2019-08-16 6:10 p.m., Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> Currently the pointer init_data is dereferenced on the assignment
> of fw_info before init_data is sanity checked to see if it is null.
> Fix te potential null pointer dereference on init_data by only
> performing dereference after it is null checked.
> 
> Addresses-Coverity: ("Dereference before null check")
> Fixes: 9adc8050bf3c ("drm/amd/display: make firmware info only load once during dc_bios create")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

Reviewed-by: Harry Wentland <harry.wentland@amd.com>

Harry

> ---
>  drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
> index bee81bf288be..926954c804a6 100644
> --- a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
> +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
> @@ -1235,7 +1235,7 @@ static bool calc_pll_max_vco_construct(
>  			struct calc_pll_clock_source_init_data *init_data)
>  {
>  	uint32_t i;
> -	struct dc_firmware_info *fw_info = &init_data->bp->fw_info;
> +	struct dc_firmware_info *fw_info;
>  	if (calc_pll_cs == NULL ||
>  			init_data == NULL ||
>  			init_data->bp == NULL)
> @@ -1244,6 +1244,7 @@ static bool calc_pll_max_vco_construct(
>  	if (init_data->bp->fw_info_valid)
>  		return false;
>  
> +	fw_info = &init_data->bp->fw_info;
>  	calc_pll_cs->ctx = init_data->ctx;
>  	calc_pll_cs->ref_freq_khz = fw_info->pll_info.crystal_frequency;
>  	calc_pll_cs->min_vco_khz =
> 

^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH][drm-next] drm/amd/display: fix a potential null pointer dereference
  2019-08-22 19:21 ` Harry Wentland
@ 2019-08-22 20:55   ` Alex Deucher
  0 siblings, 0 replies; 4+ messages in thread
From: Alex Deucher @ 2019-08-22 20:55 UTC (permalink / raw)
  To: Harry Wentland
  Cc: Colin King, Wentland, Harry, Li, Sun peng (Leo),
	Deucher, Alexander, Koenig, Christian, Zhou, David(ChunMing),
	David Airlie, Daniel Vetter, amd-gfx, dri-devel, kernel-janitors,
	linux-kernel

On Thu, Aug 22, 2019 at 3:21 PM Harry Wentland <hwentlan@amd.com> wrote:
>
> On 2019-08-16 6:10 p.m., Colin King wrote:
> > From: Colin Ian King <colin.king@canonical.com>
> >
> > Currently the pointer init_data is dereferenced on the assignment
> > of fw_info before init_data is sanity checked to see if it is null.
> > Fix te potential null pointer dereference on init_data by only
> > performing dereference after it is null checked.
> >
> > Addresses-Coverity: ("Dereference before null check")
> > Fixes: 9adc8050bf3c ("drm/amd/display: make firmware info only load once during dc_bios create")
> > Signed-off-by: Colin Ian King <colin.king@canonical.com>
>
> Reviewed-by: Harry Wentland <harry.wentland@amd.com>
>

Applied.  Thanks!

Alex

> Harry
>
> > ---
> >  drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
> > index bee81bf288be..926954c804a6 100644
> > --- a/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
> > +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c
> > @@ -1235,7 +1235,7 @@ static bool calc_pll_max_vco_construct(
> >                       struct calc_pll_clock_source_init_data *init_data)
> >  {
> >       uint32_t i;
> > -     struct dc_firmware_info *fw_info = &init_data->bp->fw_info;
> > +     struct dc_firmware_info *fw_info;
> >       if (calc_pll_cs == NULL ||
> >                       init_data == NULL ||
> >                       init_data->bp == NULL)
> > @@ -1244,6 +1244,7 @@ static bool calc_pll_max_vco_construct(
> >       if (init_data->bp->fw_info_valid)
> >               return false;
> >
> > +     fw_info = &init_data->bp->fw_info;
> >       calc_pll_cs->ctx = init_data->ctx;
> >       calc_pll_cs->ref_freq_khz = fw_info->pll_info.crystal_frequency;
> >       calc_pll_cs->min_vco_khz =
> >
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-08-22 20:55 UTC | newest]

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2019-08-16 22:10 [PATCH][drm-next] drm/amd/display: fix a potential null pointer dereference Colin King
2019-08-17  6:51 ` Dan Carpenter
2019-08-22 19:21 ` Harry Wentland
2019-08-22 20:55   ` Alex Deucher

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