commit a3b2c8c7aa1ca860edcf0b0afa371d9eb2269c3c
author Mathias Krause <minipli@googlemail.com> Fri May 31 23:24:29 2013 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> Mon Jun 03 13:55:02 2013 -0700
tree 45f73dde89f44a0dd67e26859effd3cbe90286d8
parent 3a76e5e09fbb51e756b4e732e3e65446f4984cf5

debugfs: write_file_bool() - ensure strtobool() operates on valid data

In case, userland writes an empty string to a bool debugfs file, buf[]
will still be uninitialized when being passed to strtobool() making the
outcome of that function purely random.

Fix this by always zero-terminating the buffer.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/debugfs/file.c

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index ff64bcd..6314629 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -473,6 +473,7 @@
 	if (copy_from_user(buf, user_buf, buf_size))
 		return -EFAULT;
 
+	buf[buf_size] = '\0';
 	if (strtobool(buf, &bv) == 0)
 		*val = bv;