Re: [PATCH] rtlwifi: fix potential NULL pointer dereference

[Kangjie Lu <kjlu@xxxxxxx>]

Thanks for reporting the cases. There are still a few more such
cases; we will report them soon.

On 3/12/19 4:06 AM, pkshih@xxxxxxxxxxx wrote:
> From: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
>
> In case dev_alloc_skb fails, the fix safely returns to avoid
> potential NULL pointer dereference.
>
> Signed-off-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
> ---
>   drivers/net/wireless/realtek/rtlwifi/rtl8188ee/fw.c       | 2 ++
>   drivers/net/wireless/realtek/rtlwifi/rtl8192c/fw_common.c | 2 ++
>   drivers/net/wireless/realtek/rtlwifi/rtl8192ee/fw.c       | 2 ++
>   drivers/net/wireless/realtek/rtlwifi/rtl8723ae/fw.c       | 2 ++
>   drivers/net/wireless/realtek/rtlwifi/rtl8723be/fw.c       | 2 ++
>   drivers/net/wireless/realtek/rtlwifi/rtl8821ae/fw.c       | 4 ++++
>   6 files changed, 14 insertions(+)
>
> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/fw.c b/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/fw.c
> index 203e7b574e84..e2e0bfbc24fe 100644
> --- a/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/fw.c
> +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8188ee/fw.c
> @@ -600,6 +600,8 @@ void rtl88e_set_fw_rsvdpagepkt(struct ieee80211_hw *hw, bool b_dl_finished)
>   		      u1rsvdpageloc, 3);
>   
>   	skb = dev_alloc_skb(totalpacketlen);
> +	if (!skb)
> +		return;
>   	skb_put_data(skb, &reserved_page_packet, totalpacketlen);
>   
>   	rtstatus = rtl_cmd_send_packet(hw, skb);
> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192c/fw_common.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192c/fw_common.c
> index 18c76990a089..86b1b88cc4ed 100644
> --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192c/fw_common.c
> +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192c/fw_common.c
> @@ -623,6 +623,8 @@ void rtl92c_set_fw_rsvdpagepkt(struct ieee80211_hw *hw,
>   		      u1rsvdpageloc, 3);
>   
>   	skb = dev_alloc_skb(totalpacketlen);
> +	if (!skb)
> +		return;
>   	skb_put_data(skb, &reserved_page_packet, totalpacketlen);
>   
>   	if (cmd_send_packet)
> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192ee/fw.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192ee/fw.c
> index 7c5b54b71a92..67305ce915ec 100644
> --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192ee/fw.c
> +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192ee/fw.c
> @@ -744,6 +744,8 @@ void rtl92ee_set_fw_rsvdpagepkt(struct ieee80211_hw *hw, bool b_dl_finished)
>   		      u1rsvdpageloc, 3);
>   
>   	skb = dev_alloc_skb(totalpacketlen);
> +	if (!skb)
> +		return;
>   	skb_put_data(skb, &reserved_page_packet, totalpacketlen);
>   
>   	rtstatus = rtl_cmd_send_packet(hw, skb);
> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8723ae/fw.c b/drivers/net/wireless/realtek/rtlwifi/rtl8723ae/fw.c
> index be451a6f7dbe..33481232fad0 100644
> --- a/drivers/net/wireless/realtek/rtlwifi/rtl8723ae/fw.c
> +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8723ae/fw.c
> @@ -448,6 +448,8 @@ void rtl8723e_set_fw_rsvdpagepkt(struct ieee80211_hw *hw, bool b_dl_finished)
>   		      u1rsvdpageloc, 3);
>   
>   	skb = dev_alloc_skb(totalpacketlen);
> +	if (!skb)
> +		return;
>   	skb_put_data(skb, &reserved_page_packet, totalpacketlen);
>   
>   	rtstatus = rtl_cmd_send_packet(hw, skb);
> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8723be/fw.c b/drivers/net/wireless/realtek/rtlwifi/rtl8723be/fw.c
> index 4d7fa27f55ca..aa56058af56e 100644
> --- a/drivers/net/wireless/realtek/rtlwifi/rtl8723be/fw.c
> +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8723be/fw.c
> @@ -562,6 +562,8 @@ void rtl8723be_set_fw_rsvdpagepkt(struct ieee80211_hw *hw,
>   		      u1rsvdpageloc, sizeof(u1rsvdpageloc));
>   
>   	skb = dev_alloc_skb(totalpacketlen);
> +	if (!skb)
> +		return;
>   	skb_put_data(skb, &reserved_page_packet, totalpacketlen);
>   
>   	rtstatus = rtl_cmd_send_packet(hw, skb);
> diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8821ae/fw.c b/drivers/net/wireless/realtek/rtlwifi/rtl8821ae/fw.c
> index dc0eb692088f..fe32d397d287 100644
> --- a/drivers/net/wireless/realtek/rtlwifi/rtl8821ae/fw.c
> +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8821ae/fw.c
> @@ -1623,6 +1623,8 @@ void rtl8812ae_set_fw_rsvdpagepkt(struct ieee80211_hw *hw,
>   		      &reserved_page_packet_8812[0], totalpacketlen);
>   
>   	skb = dev_alloc_skb(totalpacketlen);
> +	if (!skb)
> +		return;
>   	skb_put_data(skb, &reserved_page_packet_8812, totalpacketlen);
>   
>   	rtstatus = rtl_cmd_send_packet(hw, skb);
> @@ -1759,6 +1761,8 @@ void rtl8821ae_set_fw_rsvdpagepkt(struct ieee80211_hw *hw,
>   		      &reserved_page_packet_8821[0], totalpacketlen);
>   
>   	skb = dev_alloc_skb(totalpacketlen);
> +	if (!skb)
> +		return;
>   	skb_put_data(skb, &reserved_page_packet_8821, totalpacketlen);
>   
>   	rtstatus = rtl_cmd_send_packet(hw, skb);