On Tue, Sep 29, 2015 at 05:21:28PM +0200, PaX Team wrote:
> hi all,
>
> in drivers/net/wireless/mwifiex/sta_ioctl.c the following functions
>
> mwifiex_set_wpa_ie_helper
> mwifiex_set_wapi_ie
> mwifiex_set_wps_ie
>
> can truncate the incoming ie_len argument from u16 to u8 when it gets
> stored in mwifiex_private.wpa_ie_len, mwifiex_private.wapi_ie_len and
> mwifiex_private.wps_ie_len, respectively. based on some light code
> reading it seems a length value of 256 is valid (IEEE_MAX_IE_SIZE and
> MWIFIEX_MAX_VSIE_LEN seem to limit it) and thus would get truncated
> to 0 when stored in those u8 fields. the question is whether this is
> intentional or a bug somewhere.
i agree, while there is a test to ensure ie_len is not greater than
256, there is a possibility that it will be exactly 256, which means
256 bytes will be given to memcpy but
mwifiex_private.{wpa,wapi,wps}_ie_len will be zero.
i suggest changing the lengths to u16. not tested.
diff --git a/drivers/net/wireless/mwifiex/main.h b/drivers/net/wireless/mwifiex/main.h
index fe12560..b66e9a7 100644
--- a/drivers/net/wireless/mwifiex/main.h
+++ b/drivers/net/wireless/mwifiex/main.h
@@ -512,14 +512,14 @@ struct mwifiex_private {
struct mwifiex_wep_key wep_key[NUM_WEP_KEYS];
u16 wep_key_curr_index;
u8 wpa_ie[256];
- u8 wpa_ie_len;
+ u16 wpa_ie_len;
u8 wpa_is_gtk_set;
struct host_cmd_ds_802_11_key_material aes_key;
struct host_cmd_ds_802_11_key_material_v2 aes_key_v2;
u8 wapi_ie[256];
- u8 wapi_ie_len;
+ u16 wapi_ie_len;
u8 *wps_ie;
- u8 wps_ie_len;
+ u16 wps_ie_len;
u8 wmm_required;
u8 wmm_enabled;
u8 wmm_qosinfo;
--
James Cameron
http://quozl.linux.org.au/
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