Re: [PATCH v2] target: fix a missing check of match_int

[Mike Christie]

On 01/11/2019 11:31 PM, Kangjie Lu wrote:
> When match_int fails, "arg" is left uninitialized and may contain random
> value, thus should not be used.
> The fix checks if match_int fails, and if so, returns its error code.
> 
> Signed-off-by: Kangjie Lu 
> ---
>  drivers/target/target_core_rd.c | 15 +--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
> index a6e8106abd6f..3b7657b2f2f1 100644
> --- a/drivers/target/target_core_rd.c
> +++ b/drivers/target/target_core_rd.c
> @@ -559,6 +559,7 @@ static ssize_t rd_set_configfs_dev_params(struct 
> se_device *dev,
>   char *orig, *ptr, *opts;
>   substring_t args[MAX_OPT_ARGS];
>   int arg, token;
> + int ret;
>  
>   opts = kstrdup(page, GFP_KERNEL);
>   if (!opts)
> @@ -573,14 +574,24 @@ static ssize_t rd_set_configfs_dev_params(struct 
> se_device *dev,
>   token = match_token(ptr, tokens, args);
>   switch (token) {
>   case Opt_rd_pages:
> - match_int(args, );
> + ret = match_int(args, );
> + if (ret) {
> + kfree(orig);
> + return ret;

Just set ret to the return value and then break, so all the error and
success paths are going through the same code path.

[PATCH v2] target: fix a missing check of match_int

[Kangjie Lu]

When match_int fails, "arg" is left uninitialized and may contain random
value, thus should not be used.
The fix checks if match_int fails, and if so, returns its error code.

Signed-off-by: Kangjie Lu 
---
 drivers/target/target_core_rd.c | 15 +--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
index a6e8106abd6f..3b7657b2f2f1 100644
--- a/drivers/target/target_core_rd.c
+++ b/drivers/target/target_core_rd.c
@@ -559,6 +559,7 @@ static ssize_t rd_set_configfs_dev_params(struct se_device 
*dev,
char *orig, *ptr, *opts;
substring_t args[MAX_OPT_ARGS];
int arg, token;
+   int ret;
 
opts = kstrdup(page, GFP_KERNEL);
if (!opts)
@@ -573,14 +574,24 @@ static ssize_t rd_set_configfs_dev_params(struct 
se_device *dev,
token = match_token(ptr, tokens, args);
switch (token) {
case Opt_rd_pages:
-   match_int(args, );
+   ret = match_int(args, );
+   if (ret) {
+   kfree(orig);
+   return ret;
+   }
+
rd_dev->rd_page_count = arg;
pr_debug("RAMDISK: Referencing Page"
" Count: %u\n", rd_dev->rd_page_count);
rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
break;
case Opt_rd_nullio:
-   match_int(args, );
+   ret = match_int(args, );
+   if (ret) {
+   kfree(orig);
+   return ret;
+   }
+
if (arg != 1)
break;
 
-- 
2.17.2 (Apple Git-113)