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 <[email protected]>
---
fs/debugfs/file.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index c5ca6ae..b15a1c5 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -431,6 +431,7 @@ static ssize_t write_file_bool(struct file *file, const char __user *user_buf,
if (copy_from_user(buf, user_buf, buf_size))
return -EFAULT;
+ buf[buf_size] = '\0';
if (strtobool(buf, &bv) == 0)
*val = bv;
--
1.7.10.4