diff options
| author | raghavendra ambadas <rambad@codeaurora.org> | 2019-05-22 17:14:21 +0530 |
|---|---|---|
| committer | raghavendra ambadas <rambad@codeaurora.org> | 2019-05-28 11:54:47 +0530 |
| commit | 01fcd88c0f94f0e18b6a482de5ba17e7fa331291 (patch) | |
| tree | 82c497c557f7f497b02af92d71b9787db409b055 | |
| parent | 14ff0dc12ed0f303ca432174d0c5b142a0299172 (diff) | |
fbdev: msm: check the length of the external input buffer properly
dchdr->dlen is a short variable controlled by the user-provided data.
If the value is negative, loop continues, also increasing the value
of "len". As a result buffer overflow occurs. So define the len as
unsigned and check with length of string input from user space.
Change-Id: I8bb9ab33d543c826eb330e16ae116385d823ca98
Signed-off-by: raghavendra ambadas <rambad@codeaurora.org>
| -rw-r--r-- | drivers/video/fbdev/msm/mdss_dsi.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/video/fbdev/msm/mdss_dsi.c b/drivers/video/fbdev/msm/mdss_dsi.c index 695db66d8c26..419991a98d4e 100644 --- a/drivers/video/fbdev/msm/mdss_dsi.c +++ b/drivers/video/fbdev/msm/mdss_dsi.c @@ -1,4 +1,4 @@ -/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved. +/* Copyright (c) 2012-2019, 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 @@ -925,7 +925,8 @@ static ssize_t mdss_dsi_cmd_write(struct file *file, const char __user *p, static int mdss_dsi_cmd_flush(struct file *file, fl_owner_t id) { struct buf_data *pcmds = file->private_data; - int blen, len, i; + unsigned int len; + int blen, i; char *buf, *bufp, *bp; struct dsi_ctrl_hdr *dchdr; @@ -968,7 +969,7 @@ static int mdss_dsi_cmd_flush(struct file *file, fl_owner_t id) while (len >= sizeof(*dchdr)) { dchdr = (struct dsi_ctrl_hdr *)bp; dchdr->dlen = ntohs(dchdr->dlen); - if (dchdr->dlen > len || dchdr->dlen < 0) { + if (dchdr->dlen > (len - sizeof(*dchdr)) || dchdr->dlen < 0) { pr_err("%s: dtsi cmd=%x error, len=%d\n", __func__, dchdr->dtype, dchdr->dlen); kfree(buf); |