fbdev: msm: check buffer size before writing to user buffer

Check the number of bytes to copy against the size of the
user buffer before copy to user to avoid buffer overflow.

Change-Id: Icdd3d4e755deca19fa431e903620bd9e4c701c89
Signed-off-by: Harsh Sahu <hsahu@codeaurora.org>
This commit is contained in:
Harsh Sahu 2018-03-23 00:15:52 -07:00 committed by Gerrit - the friendly Code Review server
parent 7405e11851
commit d24de74649

View file

@ -1,4 +1,4 @@
/* Copyright (c) 2014-2017, The Linux Foundation. All rights reserved.
/* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
@ -755,6 +755,11 @@ static ssize_t mdss_xlog_dump_read(struct file *file, char __user *buff,
if (__mdss_xlog_dump_calc_range()) {
len = mdss_xlog_dump_entry(xlog_buf, MDSS_XLOG_BUF_MAX);
if (len < 0 || len > count) {
pr_err("len is more than the size of user buffer\n");
return 0;
}
if (copy_to_user(buff, xlog_buf, len))
return -EFAULT;
*ppos += len;