diff options
| author | Adrian Salido <salidoa@google.com> | 2017-04-25 16:55:26 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-12 15:01:02 +0200 |
| commit | c4c592b2c137e4451b7fdf76700ae9c98db133f5 (patch) | |
| tree | 1a6e6e96c020843ae943c6cd483ee2e57214fca4 /drivers/base | |
| parent | 26ff065b8401efd17cabf094f82f611f98acf022 (diff) | |
driver core: platform: fix race condition with driver_override
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>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/platform.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/base/platform.c b/drivers/base/platform.c index c4af00385502..5eba47815bb6 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -856,7 +856,7 @@ static ssize_t driver_override_store(struct device *dev, 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; @@ -869,12 +869,15 @@ static ssize_t driver_override_store(struct device *dev, 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); @@ -885,8 +888,12 @@ static ssize_t driver_override_show(struct device *dev, 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); |