Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763386AbYBHQvk (ORCPT ); Fri, 8 Feb 2008 11:51:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763227AbYBHQvT (ORCPT ); Fri, 8 Feb 2008 11:51:19 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:54785 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763195AbYBHQvR (ORCPT ); Fri, 8 Feb 2008 11:51:17 -0500 Date: Fri, 8 Feb 2008 08:49:14 -0800 From: Greg KH To: torvalds@linux-foundation.org Cc: Jens Axboe , Andrew Morton , cliph@research.coseinc.com, linux-kernel@vger.kernel.org Subject: [PATCH] splice: missing user pointer access verification (CVE-2008-0009/10) Message-ID: <20080208164914.GB17072@kroah.com> References: <0802051044200.29525@mjc.redhat.com> <20080205165301.1e0b8ad8.akpm@linux-foundation.org> <20080206095510.GA15220@kernel.dk> <20080207223146.GI19310@kroah.com> <20080208160203.GB23197@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080208160203.GB23197@kernel.dk> User-Agent: Mutt/1.5.16 (2007-06-09) X-Bad-Reply: References and In-Reply-To but no 'Re:' in Subject. Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1565 Lines: 55 From: Jens Axboe vmsplice_to_user() must always check the user pointer and length with access_ok() before copying. Likewise, for the slow path of copy_from_user_mmap_sem() we need to check that we may read from the user region. Signed-off-by: Jens Axboe Cc: Wojciech Purczynski Signed-off-by: Greg Kroah-Hartman --- Linus, this fixes a security hole in splice that is now public. I have it queued up for the .23 and .24 -stable releases as well. fs/splice.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/fs/splice.c b/fs/splice.c index 4ee49e8..14e2262 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -1179,6 +1179,9 @@ static int copy_from_user_mmap_sem(void *dst, const void __user *src, size_t n) { int partial; + if (!access_ok(VERIFY_READ, src, n)) + return -EFAULT; + pagefault_disable(); partial = __copy_from_user_inatomic(dst, src, n); pagefault_enable(); @@ -1387,6 +1390,11 @@ static long vmsplice_to_user(struct file *file, const struct iovec __user *iov, break; } + if (unlikely(!access_ok(VERIFY_WRITE, base, len))) { + error = -EFAULT; + break; + } + sd.len = 0; sd.total_len = len; sd.flags = flags; -- 1.5.4.22.g7a20 -- Jens Axboe -- 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/