commit c9b8be56437e57fc58cff19c03870c02fc409de3
author Sushant Kaushik <skaushik@qti.qualcomm.com> Wed Jul 15 16:41:27 2015 +0530
committer Satyanarayana Dash <sadash@codeaurora.org> Wed Jul 15 19:52:49 2015 +0530
tree efc70b281b0988848ebc9fdd75aef9ea186bd1d0
parent 4da7ec9b08ccf17646fdc690f3f1fdc9957d68da

wlan: Fix buffer overwrite problem in GETROAMSCANCHANNELS

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: I70c6c4db1c7a83e614a6d4bc40a7d7ebca138568
CRs-Fixed: 865581

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 7e2075a..a8e9f78 100755
--- a/CORE/HDD/src/wlan_hdd_main.c
+++ b/CORE/HDD/src/wlan_hdd_main.c
@@ -2822,7 +2822,8 @@
                        ChannelList[j]);
            }
 
-           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__);