diff mbox series

[ndctl,v2,1/3] cxl/region: fix a dereferecnce after NULL check

Message ID 20220823074527.404435-2-vishal.l.verma@intel.com (mailing list archive)
State Accepted
Commit cc2766399882001880a899e723c7bd968e60f100
Headers show
Series cxl: static analysis fixes | expand

Commit Message

Verma, Vishal L Aug. 23, 2022, 7:45 a.m. UTC
A NULL check in region_action() implies that 'decoder' might be NULL, but
later we dereference it during cxl_decoder_foreach(). The NULL check is
valid because it was the filter result being checked, however, while
doing this, the original 'decoder' variable was being clobbered.

Check the filter results independently of the original decoder variable.

Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
 cxl/region.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

Comments

Dan Williams Aug. 23, 2022, 5:25 p.m. UTC | #1
Vishal Verma wrote:
> A NULL check in region_action() implies that 'decoder' might be NULL, but
> later we dereference it during cxl_decoder_foreach(). The NULL check is
> valid because it was the filter result being checked, however, while
> doing this, the original 'decoder' variable was being clobbered.
> 
> Check the filter results independently of the original decoder variable.
> 
> Cc: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
> ---
>  cxl/region.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/cxl/region.c b/cxl/region.c
> index a30313c..334fcc2 100644
> --- a/cxl/region.c
> +++ b/cxl/region.c
> @@ -686,9 +686,8 @@ static int region_action(int argc, const char **argv, struct cxl_ctx *ctx,
>  			continue;
>  
>  		cxl_decoder_foreach (port, decoder) {
> -			decoder = util_cxl_decoder_filter(decoder,
> -							  param.root_decoder);
> -			if (!decoder)
> +			if (!util_cxl_decoder_filter(decoder,
> +						     param.root_decoder))
>  				continue;

Looks good.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Dave Jiang Aug. 24, 2022, 12:03 a.m. UTC | #2
On 8/23/2022 12:45 AM, Vishal Verma wrote:
> A NULL check in region_action() implies that 'decoder' might be NULL, but
> later we dereference it during cxl_decoder_foreach(). The NULL check is
> valid because it was the filter result being checked, however, while
> doing this, the original 'decoder' variable was being clobbered.
>
> Check the filter results independently of the original decoder variable.
>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
>   cxl/region.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/cxl/region.c b/cxl/region.c
> index a30313c..334fcc2 100644
> --- a/cxl/region.c
> +++ b/cxl/region.c
> @@ -686,9 +686,8 @@ static int region_action(int argc, const char **argv, struct cxl_ctx *ctx,
>   			continue;
>   
>   		cxl_decoder_foreach (port, decoder) {
> -			decoder = util_cxl_decoder_filter(decoder,
> -							  param.root_decoder);
> -			if (!decoder)
> +			if (!util_cxl_decoder_filter(decoder,
> +						     param.root_decoder))
>   				continue;
>   			rc = decoder_region_action(p, decoder, action, count);
>   			if (rc)
Jonathan Cameron Aug. 24, 2022, 9:30 a.m. UTC | #3
On Tue, 23 Aug 2022 01:45:25 -0600
Vishal Verma <vishal.l.verma@intel.com> wrote:

> A NULL check in region_action() implies that 'decoder' might be NULL, but
> later we dereference it during cxl_decoder_foreach(). The NULL check is
> valid because it was the filter result being checked, however, while
> doing this, the original 'decoder' variable was being clobbered.
> 
> Check the filter results independently of the original decoder variable.
> 
> Cc: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>

Typo in patch title.

> ---
>  cxl/region.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/cxl/region.c b/cxl/region.c
> index a30313c..334fcc2 100644
> --- a/cxl/region.c
> +++ b/cxl/region.c
> @@ -686,9 +686,8 @@ static int region_action(int argc, const char **argv, struct cxl_ctx *ctx,
>  			continue;
>  
>  		cxl_decoder_foreach (port, decoder) {
> -			decoder = util_cxl_decoder_filter(decoder,
> -							  param.root_decoder);
> -			if (!decoder)
> +			if (!util_cxl_decoder_filter(decoder,
> +						     param.root_decoder))
>  				continue;
>  			rc = decoder_region_action(p, decoder, action, count);
>  			if (rc)
diff mbox series

Patch

diff --git a/cxl/region.c b/cxl/region.c
index a30313c..334fcc2 100644
--- a/cxl/region.c
+++ b/cxl/region.c
@@ -686,9 +686,8 @@  static int region_action(int argc, const char **argv, struct cxl_ctx *ctx,
 			continue;
 
 		cxl_decoder_foreach (port, decoder) {
-			decoder = util_cxl_decoder_filter(decoder,
-							  param.root_decoder);
-			if (!decoder)
+			if (!util_cxl_decoder_filter(decoder,
+						     param.root_decoder))
 				continue;
 			rc = decoder_region_action(p, decoder, action, count);
 			if (rc)