From 1fc8a117865b54590acd773a55fbac9221b018f0 Mon Sep 17 00:00:00 2001 From: Joel Becker Date: Wed, 29 Sep 2010 17:33:05 -0700 Subject: [PATCH] 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 Cc: stable@kernel.org --- fs/ocfs2/symlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ocfs2/symlink.c b/fs/ocfs2/symlink.c index 32499d213fc4..9975457c981f 100644 --- a/fs/ocfs2/symlink.c +++ b/fs/ocfs2/symlink.c @@ -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; -- 2.20.1