Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752892AbYLSUs1 (ORCPT ); Fri, 19 Dec 2008 15:48:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752142AbYLSUrb (ORCPT ); Fri, 19 Dec 2008 15:47:31 -0500 Received: from kumera.dghda.com ([80.68.90.171]:35266 "EHLO kumera.dghda.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751763AbYLSUr3 (ORCPT ); Fri, 19 Dec 2008 15:47:29 -0500 From: "Duane Griffin" To: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, Al Viro , Andrew Morton , Duane Griffin , Tyler Hicks , Dustin Kirkland , ecryptfs-devel@lists.launchpad.net Subject: [PATCH, v5] eCryptfs: check readlink result was not an error before using it Date: Fri, 19 Dec 2008 20:47:10 +0000 Message-Id: <1229719638-6982-3-git-send-email-duaneg@dghda.com> X-Mailer: git-send-email 1.6.0.4 In-Reply-To: <1229719638-6982-2-git-send-email-duaneg@dghda.com> References: <1229719638-6982-1-git-send-email-duaneg@dghda.com> <1229719638-6982-2-git-send-email-duaneg@dghda.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1362 Lines: 41 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 --- Unchanged from original version. fs/ecryptfs/inode.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 89209f0..5e78fc1 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; -- 1.6.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/