Re: [PATCH for-4.5] watchdog/rc32434_wdt: fix ioctl error handling
From: Guenter Roeck <linux@roeck-us.net>
Date: 2016-02-28 15:56:59
Also in:
linux-watchdog, lkml
On 02/28/2016 07:44 AM, Michael S. Tsirkin wrote:
Calling return copy_to_user(...) in an ioctl will not do the right thing if there's a pagefault: copy_to_user returns the number of bytes not copied in this case. Fix up watchdog/rc32434_wdt to do return copy_to_user(...)) ? -EFAULT : 0; instead. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
quoted hunk ↗ jump to hunk
--- Untested. drivers/watchdog/rc32434_wdt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/watchdog/rc32434_wdt.c b/drivers/watchdog/rc32434_wdt.c index 71e78ef..3a75f3b 100644 --- a/drivers/watchdog/rc32434_wdt.c +++ b/drivers/watchdog/rc32434_wdt.c@@ -237,7 +237,7 @@ static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd, return -EINVAL; /* Fall through */ case WDIOC_GETTIMEOUT: - return copy_to_user(argp, &timeout, sizeof(int)); + return copy_to_user(argp, &timeout, sizeof(int)) ? -EFAULT : 0; default: return -ENOTTY; }