From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 7 Jul 2017 07:51:42 +0000 (+0200)
Subject: 4.12-stable patches
X-Git-Tag: v4.9.37~44
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=33ee35ed4b4bf82c4f7f3468b804b74b4b70e07a;p=thirdparty%2Fkernel%2Fstable-queue.git

4.12-stable patches

added patches:
	driver-core-platform-fix-race-condition-with-driver_override.patch
---

diff --git a/queue-4.12/driver-core-platform-fix-race-condition-with-driver_override.patch b/queue-4.12/driver-core-platform-fix-race-condition-with-driver_override.patch
new file mode 100644
index 00000000000..d1e0120ec21
--- /dev/null
+++ b/queue-4.12/driver-core-platform-fix-race-condition-with-driver_override.patch
@@ -0,0 +1,63 @@
+From 6265539776a0810b7ce6398c27866ddb9c6bd154 Mon Sep 17 00:00:00 2001
+From: Adrian Salido <salidoa@google.com>
+Date: Tue, 25 Apr 2017 16:55:26 -0700
+Subject: driver core: platform: fix race condition with driver_override
+
+From: Adrian Salido <salidoa@google.com>
+
+commit 6265539776a0810b7ce6398c27866ddb9c6bd154 upstream.
+
+The driver_override implementation is susceptible to race condition when
+different threads are reading vs storing a different driver override.
+Add locking to avoid race condition.
+
+Fixes: 3d713e0e382e ("driver core: platform: add device binding path 'driver_override'")
+Cc: stable@vger.kernel.org
+Signed-off-by: Adrian Salido <salidoa@google.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/base/platform.c |   11 +++++++++--
+ 1 file changed, 9 insertions(+), 2 deletions(-)
+
+--- a/drivers/base/platform.c
++++ b/drivers/base/platform.c
+@@ -866,7 +866,7 @@ static ssize_t driver_override_store(str
+ 				     const char *buf, size_t count)
+ {
+ 	struct platform_device *pdev = to_platform_device(dev);
+-	char *driver_override, *old = pdev->driver_override, *cp;
++	char *driver_override, *old, *cp;
+ 
+ 	if (count > PATH_MAX)
+ 		return -EINVAL;
+@@ -879,12 +879,15 @@ static ssize_t driver_override_store(str
+ 	if (cp)
+ 		*cp = '\0';
+ 
++	device_lock(dev);
++	old = pdev->driver_override;
+ 	if (strlen(driver_override)) {
+ 		pdev->driver_override = driver_override;
+ 	} else {
+ 		kfree(driver_override);
+ 		pdev->driver_override = NULL;
+ 	}
++	device_unlock(dev);
+ 
+ 	kfree(old);
+ 
+@@ -895,8 +898,12 @@ static ssize_t driver_override_show(stru
+ 				    struct device_attribute *attr, char *buf)
+ {
+ 	struct platform_device *pdev = to_platform_device(dev);
++	ssize_t len;
+ 
+-	return sprintf(buf, "%s\n", pdev->driver_override);
++	device_lock(dev);
++	len = sprintf(buf, "%s\n", pdev->driver_override);
++	device_unlock(dev);
++	return len;
+ }
+ static DEVICE_ATTR_RW(driver_override);
+