From: Mathias Krause <minipli@googlemail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org, Mathias Krause <minipli@googlemail.com>
Subject: [PATCH] debugfs: write_file_bool() - ensure strtobool() operates on valid data
Date: Fri, 31 May 2013 23:24:29 +0200 [thread overview]
Message-ID: <1370035469-18138-1-git-send-email-minipli@googlemail.com> (raw)
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>
---
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
reply other threads:[~2013-05-31 21:24 UTC|newest]
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