sync: Fix error paths

Check the return value of get_unused_fd to make sure a valid
file descriptor is returned.

Make sure to call put_unused_fd even if an error occurs before
the fd can be used.

Change-Id: I0fe8f78d9e30ecfc4d271c5d875424543dae2d0f
Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>

diff --git a/drivers/base/sync.c b/drivers/base/sync.c
index 74d06491cd4a835ae60f2ebb44e80a75abdb53d1..d12efbf0d24e1312da4bb45f18063dd1dd486914 100644 (file)
--- a/drivers/base/sync.c
+++ b/drivers/base/sync.c
@@ -650,8 +650,13 @@ static long sync_fence_ioctl_merge(struct sync_fence *fence, unsigned long arg)
        struct sync_fence *fence2, *fence3;
        struct sync_merge_data data;
 
-       if (copy_from_user(&data, (void __user *)arg, sizeof(data)))
-               return -EFAULT;
+       if (fd < 0)
+               return fd;
+
+       if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
+               err = -EFAULT;
+               goto err_put_fd;
+       }
 
        fence2 = sync_fence_fdget(data.fd2);
        if (fence2 == NULL) {