[PATCH] cgroup: fix possible memory leak

[Li Zefan <lizf@cn.fujitsu.com>]

There's a leak if copy_from_user() returns failure.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
 kernel/cgroup.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 657f8f8..28debe4 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1424,14 +1424,17 @@ static ssize_t cgroup_write_string(struct cgroup *cgrp, struct cftype *cft,
 		if (buffer == NULL)
 			return -ENOMEM;
 	}
-	if (nbytes && copy_from_user(buffer, userbuf, nbytes))
-		return -EFAULT;
+	if (nbytes && copy_from_user(buffer, userbuf, nbytes)) {
+		retval = -EFAULT;
+		goto out;
+	}
 
 	buffer[nbytes] = 0;     /* nul-terminate */
 	strstrip(buffer);
 	retval = cft->write_string(cgrp, cft, buffer);
 	if (!retval)
 		retval = nbytes;
+out:
 	if (buffer != local_buffer)
 		kfree(buffer);
 	return retval;
-- 
1.5.4.rc3