2018-12-26 07:10:05

by Kangjie Lu

Subject: [PATCH] target: fix a missing check for match_int

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, break.

Signed-off-by: Kangjie Lu <[email protected]>
---
drivers/target/target_core_rd.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
index a6e8106abd6f..3138123143e8 100644
--- a/drivers/target/target_core_rd.c
+++ b/drivers/target/target_core_rd.c
@@ -573,7 +573,8 @@ 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, &arg);
+ if (match_int(args, &arg))
+ break;
rd_dev->rd_page_count = arg;
pr_debug("RAMDISK: Referencing Page"
" Count: %u\n", rd_dev->rd_page_count);
--
2.17.2 (Apple Git-113)

2019-01-11 21:14:13

by Mike Christie

Subject: Re: [PATCH] target: fix a missing check for match_int

On 12/26/2018 12:48 AM, 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, break.
>
> Signed-off-by: Kangjie Lu <[email protected]>
> ---
> drivers/target/target_core_rd.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
> index a6e8106abd6f..3138123143e8 100644
> --- a/drivers/target/target_core_rd.c
> +++ b/drivers/target/target_core_rd.c
> @@ -573,7 +573,8 @@ 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, &arg);
> + if (match_int(args, &arg))
> + break;

I think if this fails you would want to return an error.

Also, I think you want to add a similar check for the Opt_rd_nullio call
below this chunk because arg may initialized to junk.


> rd_dev->rd_page_count = arg;
> pr_debug("RAMDISK: Referencing Page"
> " Count: %u\n", rd_dev->rd_page_count);
>

2019-01-12 05:34:14

by Kangjie Lu

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

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 <[email protected]>
---
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, &arg);
+ ret = match_int(args, &arg);
+ 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, &arg);
+ ret = match_int(args, &arg);
+ if (ret) {
+ kfree(orig);
+ return ret;
+ }
+
if (arg != 1)
break;

--
2.17.2 (Apple Git-113)

2019-01-19 19:08:08

by Mike Christie

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

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 <[email protected]>
> ---
> 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, &arg);
> + ret = match_int(args, &arg);
> + 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.