diff mbox

brcmfmac: avoid potential stack overflow in brcmf_cfg80211_start_ap()

Message ID 1473068749-22487-1-git-send-email-arend.vanspriel@broadcom.com (mailing list archive)
State Accepted
Commit ded89912156b1a47d940a0c954c43afbabd0c42c
Delegated to: Kalle Valo
Headers show

Commit Message

Arend Van Spriel Sept. 5, 2016, 9:45 a.m. UTC
User-space can choose to omit NL80211_ATTR_SSID and only provide raw
IE TLV data. When doing so it can provide SSID IE with length exceeding
the allowed size. The driver further processes this IE copying it
into a local variable without checking the length. Hence stack can be
corrupted and used as exploit.

Cc: stable@vger.kernel.org # v4.7
Reported-by: Daxing Guo <freener.gdx@gmail.com>
Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Arend Van Spriel Sept. 5, 2016, 10:37 a.m. UTC | #1
On 5-9-2016 11:45, Arend van Spriel wrote:
> User-space can choose to omit NL80211_ATTR_SSID and only provide raw
> IE TLV data. When doing so it can provide SSID IE with length exceeding
> the allowed size. The driver further processes this IE copying it
> into a local variable without checking the length. Hence stack can be
> corrupted and used as exploit.

This patch is intended for wireless-drivers repository, ie. for v4.8.

Regards,
Arend

> Cc: stable@vger.kernel.org # v4.7
> Reported-by: Daxing Guo <freener.gdx@gmail.com>
> Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
> Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
> Reviewed-by: Franky Lin <franky.lin@broadcom.com>
> Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
> ---
>  drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> index 5db56a7..b8aec5e5 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> @@ -4527,7 +4527,7 @@ brcmf_cfg80211_start_ap(struct wiphy *wiphy, struct net_device *ndev,
>  				(u8 *)&settings->beacon.head[ie_offset],
>  				settings->beacon.head_len - ie_offset,
>  				WLAN_EID_SSID);
> -		if (!ssid_ie)
> +		if (!ssid_ie || ssid_ie->len > IEEE80211_MAX_SSID_LEN)
>  			return -EINVAL;
>  
>  		memcpy(ssid_le.SSID, ssid_ie->data, ssid_ie->len);
>
Kalle Valo Sept. 7, 2016, 1:44 p.m. UTC | #2
Arend Van Spriel <arend.vanspriel@broadcom.com> wrote:
> User-space can choose to omit NL80211_ATTR_SSID and only provide raw
> IE TLV data. When doing so it can provide SSID IE with length exceeding
> the allowed size. The driver further processes this IE copying it
> into a local variable without checking the length. Hence stack can be
> corrupted and used as exploit.
> 
> Cc: stable@vger.kernel.org # v4.7
> Reported-by: Daxing Guo <freener.gdx@gmail.com>
> Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
> Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
> Reviewed-by: Franky Lin <franky.lin@broadcom.com>
> Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>

Thanks, 1 patch applied to wireless-drivers.git:

ded89912156b brcmfmac: avoid potential stack overflow in brcmf_cfg80211_start_ap()
diff mbox

Patch

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
index 5db56a7..b8aec5e5 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
@@ -4527,7 +4527,7 @@  brcmf_cfg80211_start_ap(struct wiphy *wiphy, struct net_device *ndev,
 				(u8 *)&settings->beacon.head[ie_offset],
 				settings->beacon.head_len - ie_offset,
 				WLAN_EID_SSID);
-		if (!ssid_ie)
+		if (!ssid_ie || ssid_ie->len > IEEE80211_MAX_SSID_LEN)
 			return -EINVAL;
 
 		memcpy(ssid_le.SSID, ssid_ie->data, ssid_ie->len);