Patchwork [4/4] ext3: ensure fast symlinks are NUL-terminated

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Submitter prasanna.panchamukhi@riverbed.com
Date April 20, 2011, 2:07 a.m.
Message ID <1303265260-9210-4-git-send-email-prasanna.panchamukhi@riverbed.com>
Download mbox | patch
Permalink /patch/92075/
State New
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Comments

prasanna.panchamukhi@riverbed.com - April 20, 2011, 2:07 a.m.
From: Prasanna S. Panchamukhi <ppanchamukhi@riverbed.com>

Ensure fast symlink targets are NUL-terminated, even if corrupted
on-disk.

This patch has been back ported from upstream
commit b5ed3112b5f74c8ec1c7aa03a76c596635e85197.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: linux-ext4@vger.kernel.org
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
BugID: 68873
Signed-off-by: Prasanna S. Panchamukhi <ppanchamukhi@riverbed.com>
---
 fs/ext3/inode.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

Patch

diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 67d0af8..d669d78 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -36,6 +36,7 @@ 
 #include <linux/writeback.h>
 #include <linux/mpage.h>
 #include <linux/uio.h>
+#include <linux/namei.h>
 #include "xattr.h"
 #include "acl.h"
 
@@ -2481,9 +2482,11 @@  void ext3_read_inode(struct inode * inode)
 		inode->i_op = &ext3_dir_inode_operations;
 		inode->i_fop = &ext3_dir_operations;
 	} else if (S_ISLNK(inode->i_mode)) {
-		if (ext3_inode_is_fast_symlink(inode))
+		if (ext3_inode_is_fast_symlink(inode)) {
 			inode->i_op = &ext3_fast_symlink_inode_operations;
-		else {
+			nd_terminate_link(ei->i_data, inode->i_size,
+						      sizeof(ei->i_data) - 1);
+		} else {
 			inode->i_op = &ext3_symlink_inode_operations;
 			ext3_set_aops(inode);
 		}