From: Nikanth Karthikesan <knikanth@suse.de>
Date: Sun, 16 May 2010 18:00:00 +0000 (-0400)
Subject: ext4: Prevent creation of files larger than RLIMIT_FSIZE using fallocate
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6d19c42b7cf81c39632b6d4dbc514e8449bcd346;p=mv-sheeva.git

ext4: Prevent creation of files larger than RLIMIT_FSIZE using fallocate

Currently using posix_fallocate one can bypass an RLIMIT_FSIZE limit
and create a file larger than the limit. Add a check for that.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Amit Arora <aarora@in.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index ee611daf074..8a8f9f0be91 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3708,6 +3708,11 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
 	 */
 	credits = ext4_chunk_trans_blocks(inode, max_blocks);
 	mutex_lock(&inode->i_mutex);
+	ret = inode_newsize_ok(inode, (len + offset));
+	if (ret) {
+		mutex_unlock(&inode->i_mutex);
+		return ret;
+	}
 retry:
 	while (ret >= 0 && ret < max_blocks) {
 		block = block + ret;