Commit 1fc8a117 authored Sep 29, 2010 by Joel Becker

ocfs2: Don't walk off the end of fast symlinks.



ocfs2 fast symlinks are NUL terminated strings stored inline in the
inode data area.  However, disk corruption or a local attacker could, in
theory, remove that NUL.  Because we're using strlen() (my fault,
introduced in a731d1 when removing vfs_follow_link()), we could walk off
the end of that string.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Cc: stable@kernel.org

parent 899611ee

fs/ocfs2/symlink.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -128,7 +128,7 @@ static void ocfs2_fast_follow_link(struct dentry dentry,
		}

		/* Fast symlinks can't be large */
		len = strlen(target);
		len = strnlen(target, ocfs2_fast_symlink_chars(inode->i_sb));
		link = kzalloc(len + 1, GFP_NOFS);
		if (!link) {
		status = -ENOMEM;