From a17d5232de7b53d34229de79ec22f4bb04adb7e4 Mon Sep 17 00:00:00 2001 From: Duane Griffin Date: Fri, 19 Dec 2008 20:47:10 +0000 Subject: [PATCH] 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 Cc: Dustin Kirkland Cc: ecryptfs-devel@lists.launchpad.net Signed-off-by: Duane Griffin Acked-by: Michael Halcrow Acked-by: Tyler Hicks Signed-off-by: Al Viro --- fs/ecryptfs/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 89209f00f9c7..5e78fc179886 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -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; -- 2.39.2