From bf563b01c2895a4bfd1a29cc5abc67fe706ecffd Mon Sep 17 00:00:00 2001 From: Nicolai Stange Date: Mon, 11 Sep 2017 09:45:42 +0200 Subject: [PATCH] driver core: platform: Don't read past the end of "driver_override" buffer When printing the driver_override parameter when it is 4095 and 4094 bytes long, the printing code would access invalid memory because we need count+1 bytes for printing. Reject driver_override values of these lengths in driver_override_store(). This is in close analogy to commit 4efe874aace5 ("PCI: Don't read past the end of sysfs "driver_override" buffer") from Sasha Levin. Fixes: 3d713e0e382e ("driver core: platform: add device binding path 'driver_override'") Cc: stable@vger.kernel.org # v3.17+ Signed-off-by: Nicolai Stange Signed-off-by: Greg Kroah-Hartman --- drivers/base/platform.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/base/platform.c b/drivers/base/platform.c index d1bd99271066..9045c5f3734e 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -868,7 +868,8 @@ static ssize_t driver_override_store(struct device *dev, struct platform_device *pdev = to_platform_device(dev); char *driver_override, *old, *cp; - if (count > PATH_MAX) + /* We need to keep extra room for a newline */ + if (count >= (PAGE_SIZE - 1)) return -EINVAL; driver_override = kstrndup(buf, count, GFP_KERNEL);