[PATCH 1/1] cxl/hdm: Fix potential infinite loop in __cxl_dpa_reserve()

[PATCH 1/1] cxl/hdm: Fix potential infinite loop in __cxl_dpa_reserve()

[Li Ming]

In __cxl_dpa_reserve(), it will check if the new resource range is
included in one of paritions of the cxl memory device.
cxlds->nr_paritions is used to represent how many partitions information
the cxl memory device has. In the loop, if driver cannot find a
partition including the new resource range, it will be an infinite loop.

Fixes: be5cbd084027 ("cxl: Kill enum cxl_decoder_mode")
Signed-off-by: Li Ming <ming.li@zohomail.com>
---
 drivers/cxl/core/hdm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 1c5d2022c87a..a470099a69f1 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -403,7 +403,7 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
 	 * is not set.
 	 */
 	if (cxled->part < 0)
-		for (int i = 0; cxlds->nr_partitions; i++)
+		for (int i = 0; i < cxlds->nr_partitions; i++)
 			if (resource_contains(&cxlds->part[i].res, res)) {
 				cxled->part = i;
 				break;
-- 
2.34.1

Re: [PATCH 1/1] cxl/hdm: Fix potential infinite loop in __cxl_dpa_reserve()

[Dave Jiang]

On 1/12/26 5:05 AM, Li Ming wrote:
> In __cxl_dpa_reserve(), it will check if the new resource range is
> included in one of paritions of the cxl memory device.
> cxlds->nr_paritions is used to represent how many partitions information
> the cxl memory device has. In the loop, if driver cannot find a
> partition including the new resource range, it will be an infinite loop.
> 
> Fixes: be5cbd084027 ("cxl: Kill enum cxl_decoder_mode")
> Signed-off-by: Li Ming <ming.li@zohomail.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>  drivers/cxl/core/hdm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
> index 1c5d2022c87a..a470099a69f1 100644
> --- a/drivers/cxl/core/hdm.c
> +++ b/drivers/cxl/core/hdm.c
> @@ -403,7 +403,7 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
>  	 * is not set.
>  	 */
>  	if (cxled->part < 0)
> -		for (int i = 0; cxlds->nr_partitions; i++)
> +		for (int i = 0; i < cxlds->nr_partitions; i++)
>  			if (resource_contains(&cxlds->part[i].res, res)) {
>  				cxled->part = i;
>  				break;

Re: [PATCH 1/1] cxl/hdm: Fix potential infinite loop in __cxl_dpa_reserve()

[Ira Weiny]

Li Ming wrote:
> In __cxl_dpa_reserve(), it will check if the new resource range is
> included in one of paritions of the cxl memory device.
> cxlds->nr_paritions is used to represent how many partitions information
> the cxl memory device has. In the loop, if driver cannot find a
> partition including the new resource range, it will be an infinite loop.
> 
> Fixes: be5cbd084027 ("cxl: Kill enum cxl_decoder_mode")

Technically the bug was introduced in:

Fixes: 991d98f17d31 ("cxl: Make cxl_dpa_alloc() DPA partition number agnostic")

With that,
Reviewed-by: Ira Weiny <ira.weiny@intel.com>

[snip]

Re: [PATCH 1/1] cxl/hdm: Fix potential infinite loop in __cxl_dpa_reserve()

[Dave Jiang]

On 1/12/26 5:05 AM, Li Ming wrote:
> In __cxl_dpa_reserve(), it will check if the new resource range is
> included in one of paritions of the cxl memory device.
> cxlds->nr_paritions is used to represent how many partitions information
> the cxl memory device has. In the loop, if driver cannot find a
> partition including the new resource range, it will be an infinite loop.
> 
> Fixes: be5cbd084027 ("cxl: Kill enum cxl_decoder_mode")
> Signed-off-by: Li Ming <ming.li@zohomail.com>

Applied to cxl/fixes with Fixes tag fixed
d4026a44626490dc4eca4dd2c4d0816338fa179b

> ---
>  drivers/cxl/core/hdm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
> index 1c5d2022c87a..a470099a69f1 100644
> --- a/drivers/cxl/core/hdm.c
> +++ b/drivers/cxl/core/hdm.c
> @@ -403,7 +403,7 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
>  	 * is not set.
>  	 */
>  	if (cxled->part < 0)
> -		for (int i = 0; cxlds->nr_partitions; i++)
> +		for (int i = 0; i < cxlds->nr_partitions; i++)
>  			if (resource_contains(&cxlds->part[i].res, res)) {
>  				cxled->part = i;
>  				break;

Re: [PATCH] cxl/hdm: Fix potential infinite loop in __cxl_dpa_reserve()

[Markus Elfring]

> > In __cxl_dpa_reserve(), it will check if the new resource range is
> > included in one of paritions of the cxl memory device.
> > cxlds->nr_paritions is used to represent how many partitions information
…

How do you think about to avoid typos in such a change description?


> Applied to cxl/fixes with Fixes tag fixed
> d4026a44626490dc4eca4dd2c4d0816338fa179b

Is this adjustment still improvable?

Regards,
Markus