Patchwork mwifiex: avoid out of bounds access in mwifiex_get_common_rates.

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Submitter Cyril Roelandt
Date Jan. 27, 2013, 10:42 p.m.
Message ID <1359326568-17022-1-git-send-email-tipecaml@gmail.com>
Download mbox | patch
Permalink /patch/216078/
State Not Applicable
Delegated to: David Miller
Headers show

Comments

Cyril Roelandt - Jan. 27, 2013, 10:42 p.m.
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 <tipecaml@gmail.com>
---
 drivers/net/wireless/mwifiex/join.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
Bing Zhao - Jan. 28, 2013, 6:53 p.m.
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 <tipecaml@gmail.com>

Acked-by: Bing Zhao <bzhao@marvell.com>

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

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Patch

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)) {