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 (file)
index 0000000..d1e0120
--- /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);
+