commit 231a445351479e381baac36f46fd1cf1eae9a9a8
author Sushant Kaushik <skaushik@qti.qualcomm.com> Wed Jul 15 16:23:56 2015 +0530
committer Satyanarayana Dash <sadash@codeaurora.org> Wed Jul 15 19:52:48 2015 +0530
tree 2284a9364b4c6a63179227ef863e0cb486ebd10b
parent b5c67c08aa16730f2d6af71568f317f331145244

wlan: Fix buffer overwrite problem in GETFASTTRANSITION

If (len + 1) is greater than priv_data.total_len then copy_to_user
results in writing more data than the buffer can hold.
Fix this by writing mininum of (len + 1) and priv_data.total_len.

Change-Id: Ib5c5c61704c810652206004c302c69a2243f9b5a
CRs-Fixed: 865565

CORE/HDD/src/wlan_hdd_main.c

diff --git a/CORE/HDD/src/wlan_hdd_main.c b/CORE/HDD/src/wlan_hdd_main.c
index 98ba4c4..a6fa05b 100755
--- a/CORE/HDD/src/wlan_hdd_main.c
+++ b/CORE/HDD/src/wlan_hdd_main.c
@@ -2912,7 +2912,8 @@
 
            len = scnprintf(extra, sizeof(extra), "%s %d",
                    "GETFASTTRANSITION", ft);
-           if (copy_to_user(priv_data.buf, &extra, len + 1))
+           len = VOS_MIN(priv_data.total_len, len + 1);
+           if (copy_to_user(priv_data.buf, &extra, len))
            {
                VOS_TRACE( VOS_MODULE_ID_HDD, VOS_TRACE_LEVEL_ERROR,
                   "%s: failed to copy data to user buffer", __func__);