[PATCH stable 3.16] rtlwifi: Fix potential overflow on P2P code

[PATCH stable 3.16] rtlwifi: Fix potential overflow on P2P code

[pkshih]

From: Laura Abbott <labbott@redhat.com>

commit 8c55dedb795be8ec0cf488f98c03a1c2176f7fb1 upstream.

Nicolas Waisman noticed that even though noa_len is checked for
a compatible length it's still possible to overrun the buffers
of p2pinfo since there's no check on the upper bound of noa_num.
Bound noa_num against P2P_MAX_NOA_NUM.

Reported-by: Nicolas Waisman <nico@semmle.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
---
This fix is applied to most of stable kernel excepting to 3.16 due to
directory change on kernel 4.4. So, I compose this patch with old directory
for stable kernel 3.16.
---
 drivers/net/wireless/rtlwifi/ps.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/wireless/rtlwifi/ps.c b/drivers/net/wireless/rtlwifi/ps.c
index 50504942ded1..bfe097b224ad 100644
--- a/drivers/net/wireless/rtlwifi/ps.c
+++ b/drivers/net/wireless/rtlwifi/ps.c
@@ -801,6 +801,9 @@ static void rtl_p2p_noa_ie(struct ieee80211_hw *hw, void *data,
 				return;
 			} else {
 				noa_num = (noa_len - 2) / 13;
+				if (noa_num > P2P_MAX_NOA_NUM)
+					noa_num = P2P_MAX_NOA_NUM;
+
 			}
 			noa_index = ie[3];
 			if (rtlpriv->psc.p2p_ps_info.p2p_ps_mode ==
@@ -895,6 +898,9 @@ static void rtl_p2p_action_ie(struct ieee80211_hw *hw, void *data,
 				return;
 			} else {
 				noa_num = (noa_len - 2) / 13;
+				if (noa_num > P2P_MAX_NOA_NUM)
+					noa_num = P2P_MAX_NOA_NUM;
+
 			}
 			noa_index = ie[3];
 			if (rtlpriv->psc.p2p_ps_info.p2p_ps_mode ==
-- 
2.21.0

Re: [PATCH stable 3.16] rtlwifi: Fix potential overflow on P2P code

[Ben Hutchings]

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On Tue, 2019-11-05 at 14:08 +0800, pkshih@realtek.com wrote:
> From: Laura Abbott <labbott@redhat.com>
> 
> commit 8c55dedb795be8ec0cf488f98c03a1c2176f7fb1 upstream.
> 
> Nicolas Waisman noticed that even though noa_len is checked for
> a compatible length it's still possible to overrun the buffers
> of p2pinfo since there's no check on the upper bound of noa_num.
> Bound noa_num against P2P_MAX_NOA_NUM.
> 
> Reported-by: Nicolas Waisman <nico@semmle.com>
> Signed-off-by: Laura Abbott <labbott@redhat.com>
> Acked-by: Ping-Ke Shih <pkshih@realtek.com>
> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
> ---
> This fix is applied to most of stable kernel excepting to 3.16 due to
> directory change on kernel 4.4. So, I compose this patch with old directory
> for stable kernel 3.16.

Thanks for this.  I actually got round to backporting this myself
before seeing your mail, so this ended up 3.16.77.

Ben.

> ---
>  drivers/net/wireless/rtlwifi/ps.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/net/wireless/rtlwifi/ps.c b/drivers/net/wireless/rtlwifi/ps.c
> index 50504942ded1..bfe097b224ad 100644
> --- a/drivers/net/wireless/rtlwifi/ps.c
> +++ b/drivers/net/wireless/rtlwifi/ps.c
> @@ -801,6 +801,9 @@ static void rtl_p2p_noa_ie(struct ieee80211_hw *hw, void *data,
>  				return;
>  			} else {
>  				noa_num = (noa_len - 2) / 13;
> +				if (noa_num > P2P_MAX_NOA_NUM)
> +					noa_num = P2P_MAX_NOA_NUM;
> +
>  			}
>  			noa_index = ie[3];
>  			if (rtlpriv->psc.p2p_ps_info.p2p_ps_mode ==
> @@ -895,6 +898,9 @@ static void rtl_p2p_action_ie(struct ieee80211_hw *hw, void *data,
>  				return;
>  			} else {
>  				noa_num = (noa_len - 2) / 13;
> +				if (noa_num > P2P_MAX_NOA_NUM)
> +					noa_num = P2P_MAX_NOA_NUM;
> +
>  			}
>  			noa_index = ie[3];
>  			if (rtlpriv->psc.p2p_ps_info.p2p_ps_mode ==
-- 
Ben Hutchings
If the facts do not conform to your theory, they must be disposed of.


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