2013-01-27 22:53:43

by Cyril Roelandt

Subject: [PATCH] mwifiex: avoid out of bounds access in mwifiex_get_common_rates.

Check that the array indexes are in-bounds before accessing the rate2 and tmp
arrays.

Found with the following semantic patch:

<smpl>
@@
identifier t;
identifier idx;
expression E;
statement S;
@@
* for (... ; <+... t[idx] ...+> && idx < E ; ...)
S
</smpl>

Signed-off-by: Cyril Roelandt <[email protected]>
---
drivers/net/wireless/mwifiex/join.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mwifiex/join.c b/drivers/net/wireless/mwifiex/join.c
index 893d809..f0a634d 100644
--- a/drivers/net/wireless/mwifiex/join.c
+++ b/drivers/net/wireless/mwifiex/join.c
@@ -157,8 +157,8 @@ static int mwifiex_get_common_rates(struct mwifiex_private *priv, u8 *rate1,

memset(rate1, 0, rate1_size);

- for (i = 0; rate2[i] && i < rate2_size; i++) {
- for (j = 0; tmp[j] && j < rate1_size; j++) {
+ for (i = 0; i < rate2_size && rate2[i]; i++) {
+ for (j = 0; j < rate1_size && tmp[j]; j++) {
/* Check common rate, excluding the bit for
basic rate */
if ((rate2[i] & 0x7F) == (tmp[j] & 0x7F)) {
--
1.7.10.4

2013-01-28 18:58:18

by Bing Zhao

Subject: RE: [PATCH] mwifiex: avoid out of bounds access in mwifiex_get_common_rates.

Hi Cyril,

Thanks for your patch.

> Check that the array indexes are in-bounds before accessing the rate2 and tmp
> arrays.
>
> Found with the following semantic patch:
>
> <smpl>
> @@
> identifier t;
> identifier idx;
> expression E;
> statement S;
> @@
> * for (... ; <+... t[idx] ...+> && idx < E ; ...)
> S
> </smpl>
>
> Signed-off-by: Cyril Roelandt <[email protected]>

Acked-by: Bing Zhao <[email protected]>

Thanks,
Bing

> ---
> drivers/net/wireless/mwifiex/join.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/mwifiex/join.c b/drivers/net/wireless/mwifiex/join.c
> index 893d809..f0a634d 100644
> --- a/drivers/net/wireless/mwifiex/join.c
> +++ b/drivers/net/wireless/mwifiex/join.c
> @@ -157,8 +157,8 @@ static int mwifiex_get_common_rates(struct mwifiex_private *priv, u8 *rate1,
>
> memset(rate1, 0, rate1_size);
>
> - for (i = 0; rate2[i] && i < rate2_size; i++) {
> - for (j = 0; tmp[j] && j < rate1_size; j++) {
> + for (i = 0; i < rate2_size && rate2[i]; i++) {
> + for (j = 0; j < rate1_size && tmp[j]; j++) {
> /* Check common rate, excluding the bit for
> basic rate */
> if ((rate2[i] & 0x7F) == (tmp[j] & 0x7F)) {
> --
> 1.7.10.4