Commit a17d5232 authored Dec 19, 2008 by Duane Griffin Committed by Al Viro Dec 31, 2008

eCryptfs: check readlink result was not an error before using it

The result from readlink is being used to index into the link name
buffer without checking whether it is a valid length. If readlink
returns an error this will fault or cause memory corruption.

Cc: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: ecryptfs-devel@lists.launchpad.net
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Michael Halcrow <mhalcrow@us.ibm.com>
Acked-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

parent 5cc4a034

fs/ecryptfs/inode.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -673,10 +673,11 @@ static void ecryptfs_follow_link(struct dentry dentry, struct nameidata *nd)
		ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ "
		"dentry->d_name.name = [%s]\n", dentry->d_name.name);
		rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
		buf[rc] = '\0';
		set_fs(old_fs);
		if (rc < 0)
		goto out_free;
		else
		buf[rc] = '\0';
		rc = 0;
		nd_set_link(nd, buf);
		goto out;

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