DivestOS/Patches/Linux_CVEs/CVE-2017-8266/3.18/0002.patch
2017-11-07 21:38:42 -05:00

53 lines
1.7 KiB
Diff

From 42627c94cf8c189332a6f5bfdd465ea662777911 Mon Sep 17 00:00:00 2001
From: Harsh Sahu <hsahu@codeaurora.org>
Date: Thu, 13 Apr 2017 15:38:46 -0700
Subject: msm: mdss: fix race condition during mdp debugfs release
Fix race condition in the release of the mdp debugfs functions
panel_debug_base_release and mdss_debug_base_release by adding
the lock for unpreempted freeing of the buffer so that multiple
concurrent processes cannot affect the release which can possibly
lead to use-after-free operation on the buffer.
Change-Id: I9586081b65ae2eb0e7f6e30c606ee748ae9ef7e8
Signed-off-by: Harsh Sahu <hsahu@codeaurora.org>
---
drivers/video/msm/mdss/mdss_debug.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/video/msm/mdss/mdss_debug.c b/drivers/video/msm/mdss/mdss_debug.c
index 920babf..78bfe50 100644
--- a/drivers/video/msm/mdss/mdss_debug.c
+++ b/drivers/video/msm/mdss/mdss_debug.c
@@ -57,11 +57,13 @@ static int panel_debug_base_open(struct inode *inode, struct file *file)
static int panel_debug_base_release(struct inode *inode, struct file *file)
{
struct mdss_debug_base *dbg = file->private_data;
+ mutex_lock(&mdss_debug_lock);
if (dbg && dbg->buf) {
kfree(dbg->buf);
dbg->buf_len = 0;
dbg->buf = NULL;
}
+ mutex_unlock(&mdss_debug_lock);
return 0;
}
@@ -386,11 +388,13 @@ static int mdss_debug_base_open(struct inode *inode, struct file *file)
static int mdss_debug_base_release(struct inode *inode, struct file *file)
{
struct mdss_debug_base *dbg = file->private_data;
+ mutex_lock(&mdss_debug_lock);
if (dbg && dbg->buf) {
kfree(dbg->buf);
dbg->buf_len = 0;
dbg->buf = NULL;
}
+ mutex_unlock(&mdss_debug_lock);
return 0;
}
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