[PATCH][next] wil6210: fix wil_cid_valid with negative cid values

[PATCH][next] wil6210: fix wil_cid_valid with negative cid values

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

There are several occasions where a negative cid value is passed
into wil_cid_valid and this is converted into a u8 causing the
range check of cid >= 0 to always succeed.  Fix this by making
the cid argument an int to handle any -ve error value of cid.

An example of this behaviour is in wil_cfg80211_dump_station,
where cid is assigned -ENOENT if the call to wil_find_cid_by_idx
fails, and this -ve value is passed to wil_cid_valid.  I believe
that the conversion of -ENOENT to the u8 value 254 which is
greater than wil->max_assoc_sta causes wil_find_cid_by_idx to
currently work fine, but I think is by luck and not the
intended behaviour.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/net/wireless/ath/wil6210/wil6210.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/wil6210/wil6210.h b/drivers/net/wireless/ath/wil6210/wil6210.h
index 6f456b311a39..25a1adcb38eb 100644
--- a/drivers/net/wireless/ath/wil6210/wil6210.h
+++ b/drivers/net/wireless/ath/wil6210/wil6210.h
@@ -1144,7 +1144,7 @@ static inline void wil_c(struct wil6210_priv *wil, u32 reg, u32 val)
 /**
  * wil_cid_valid - check cid is valid
  */
-static inline bool wil_cid_valid(struct wil6210_priv *wil, u8 cid)
+static inline bool wil_cid_valid(struct wil6210_priv *wil, int cid)
 {
 	return (cid >= 0 && cid < wil->max_assoc_sta);
 }
-- 
2.20.1

Re: [PATCH][next] wil6210: fix wil_cid_valid with negative cid values

[merez]

On 2019-07-02 17:40, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> There are several occasions where a negative cid value is passed
> into wil_cid_valid and this is converted into a u8 causing the
> range check of cid >= 0 to always succeed.  Fix this by making
> the cid argument an int to handle any -ve error value of cid.
> 
> An example of this behaviour is in wil_cfg80211_dump_station,
> where cid is assigned -ENOENT if the call to wil_find_cid_by_idx
> fails, and this -ve value is passed to wil_cid_valid.  I believe
> that the conversion of -ENOENT to the u8 value 254 which is
> greater than wil->max_assoc_sta causes wil_find_cid_by_idx to
> currently work fine, but I think is by luck and not the
> intended behaviour.
> 
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/net/wireless/ath/wil6210/wil6210.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/ath/wil6210/wil6210.h
> b/drivers/net/wireless/ath/wil6210/wil6210.h
> index 6f456b311a39..25a1adcb38eb 100644
> --- a/drivers/net/wireless/ath/wil6210/wil6210.h
> +++ b/drivers/net/wireless/ath/wil6210/wil6210.h
> @@ -1144,7 +1144,7 @@ static inline void wil_c(struct wil6210_priv
> *wil, u32 reg, u32 val)
>  /**
>   * wil_cid_valid - check cid is valid
>   */
> -static inline bool wil_cid_valid(struct wil6210_priv *wil, u8 cid)
> +static inline bool wil_cid_valid(struct wil6210_priv *wil, int cid)
>  {
>  	return (cid >= 0 && cid < wil->max_assoc_sta);
>  }

Reviewed-by: Maya Erez <merez@codeaurora.org>

-- 
Maya Erez
Qualcomm Israel, Inc. on behalf of Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a 
Linux Foundation Collaborative Project

Re: [PATCH][next] wil6210: fix wil_cid_valid with negative cid values

[Kalle Valo]

Colin King <colin.king@canonical.com> wrote:

> There are several occasions where a negative cid value is passed
> into wil_cid_valid and this is converted into a u8 causing the
> range check of cid >= 0 to always succeed.  Fix this by making
> the cid argument an int to handle any -ve error value of cid.
> 
> An example of this behaviour is in wil_cfg80211_dump_station,
> where cid is assigned -ENOENT if the call to wil_find_cid_by_idx
> fails, and this -ve value is passed to wil_cid_valid.  I believe
> that the conversion of -ENOENT to the u8 value 254 which is
> greater than wil->max_assoc_sta causes wil_find_cid_by_idx to
> currently work fine, but I think is by luck and not the
> intended behaviour.
> 
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> Reviewed-by: Maya Erez <merez@codeaurora.org>
> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

Patch applied to ath-next branch of ath.git, thanks.

23bb9f692b66 wil6210: fix wil_cid_valid with negative cid values

-- 
https://patchwork.kernel.org/patch/11027989/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches