mwifiex: fix use-after-free in beacon_ie processing
beacon_ie buffer is allocated in mwifiex_fill_new_bss_desc()
and the buffer pointer is saved in bss_desc->beacon_buf.
beacon_ie is freed before the function returns. However,
bss_desc->beacon_buf is still being accessed afterwards.
Fix it by freeing beacon_ie (bss_desc->beacon_buf) in
caller's scope.
Reviewed-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Paul Stewart <pstew@chromium.org>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/mwifiex/scan.c b/drivers/net/wireless/mwifiex/scan.c
index e7f6dea..37b24e8 100644
--- a/drivers/net/wireless/mwifiex/scan.c
+++ b/drivers/net/wireless/mwifiex/scan.c
@@ -1533,10 +1533,18 @@
/* Make a copy of current BSSID descriptor */
memcpy(&priv->curr_bss_params.bss_descriptor, bss_desc,
sizeof(priv->curr_bss_params.bss_descriptor));
+
+ /* The contents of beacon_ie will be copied to its own buffer
+ * in mwifiex_save_curr_bcn()
+ */
mwifiex_save_curr_bcn(priv);
spin_unlock_irqrestore(&priv->curr_bcn_buf_lock, flags);
done:
+ /* beacon_ie buffer was allocated in function
+ * mwifiex_fill_new_bss_desc(). Free it now.
+ */
+ kfree(bss_desc->beacon_buf);
kfree(bss_desc);
return 0;
}
diff --git a/drivers/net/wireless/mwifiex/sta_ioctl.c b/drivers/net/wireless/mwifiex/sta_ioctl.c
index e6c9b2a..27729cf 100644
--- a/drivers/net/wireless/mwifiex/sta_ioctl.c
+++ b/drivers/net/wireless/mwifiex/sta_ioctl.c
@@ -140,12 +140,13 @@
/*
* This function fills bss descriptor structure using provided
* information.
+ * beacon_ie buffer is allocated in this function. It is caller's
+ * responsibility to free the memory.
*/
int mwifiex_fill_new_bss_desc(struct mwifiex_private *priv,
struct cfg80211_bss *bss,
struct mwifiex_bssdescriptor *bss_desc)
{
- int ret;
u8 *beacon_ie;
size_t beacon_ie_len;
struct mwifiex_bss_priv *bss_priv = (void *)bss->priv;
@@ -165,6 +166,7 @@
memcpy(bss_desc->mac_address, bss->bssid, ETH_ALEN);
bss_desc->rssi = bss->signal;
+ /* The caller of this function will free beacon_ie */
bss_desc->beacon_buf = beacon_ie;
bss_desc->beacon_buf_size = beacon_ie_len;
bss_desc->beacon_period = bss->beacon_interval;
@@ -182,10 +184,7 @@
else
bss_desc->bss_mode = NL80211_IFTYPE_STATION;
- ret = mwifiex_update_bss_desc_with_ie(priv->adapter, bss_desc);
-
- kfree(beacon_ie);
- return ret;
+ return mwifiex_update_bss_desc_with_ie(priv->adapter, bss_desc);
}
static int mwifiex_process_country_ie(struct mwifiex_private *priv,
@@ -349,6 +348,11 @@
}
done:
+ /* beacon_ie buffer was allocated in function
+ * mwifiex_fill_new_bss_desc(). Free it now.
+ */
+ if (bss_desc)
+ kfree(bss_desc->beacon_buf);
kfree(bss_desc);
return ret;
}