From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:48018 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751477AbeBWHbv (ORCPT ); Fri, 23 Feb 2018 02:31:51 -0500 Subject: Patch "kcov: detect double association with a single task" has been added to the 4.9-stable tree To: dvyukov@google.com, akpm@linux-foundation.org, gregkh@linuxfoundation.org, sp3485@columbia.edu, syzkaller@googlegroups.com, torvalds@linux-foundation.org Cc: , From: Date: Fri, 23 Feb 2018 08:31:33 +0100 Message-ID: <1519371093140224@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled kcov: detect double association with a single task to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kcov-detect-double-association-with-a-single-task.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From a77660d231f8b3d84fd23ed482e0964f7aa546d6 Mon Sep 17 00:00:00 2001 From: Dmitry Vyukov Date: Tue, 6 Feb 2018 15:40:28 -0800 Subject: kcov: detect double association with a single task From: Dmitry Vyukov commit a77660d231f8b3d84fd23ed482e0964f7aa546d6 upstream. Currently KCOV_ENABLE does not check if the current task is already associated with another kcov descriptor. As the result it is possible to associate a single task with more than one kcov descriptor, which later leads to a memory leak of the old descriptor. This relation is really meant to be one-to-one (task has only one back link). Extend validation to detect such misuse. Link: http://lkml.kernel.org/r/20180122082520.15716-1-dvyukov@google.com Fixes: 5c9a8750a640 ("kernel: add kcov code coverage") Signed-off-by: Dmitry Vyukov Reported-by: Shankara Pailoor Cc: Dmitry Vyukov Cc: syzbot Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- kernel/kcov.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/kcov.c +++ b/kernel/kcov.c @@ -220,9 +220,9 @@ static int kcov_ioctl_locked(struct kcov if (unused != 0 || kcov->mode == KCOV_MODE_DISABLED || kcov->area == NULL) return -EINVAL; - if (kcov->t != NULL) - return -EBUSY; t = current; + if (kcov->t != NULL || t->kcov != NULL) + return -EBUSY; /* Cache in task struct for performance. */ t->kcov_size = kcov->size; t->kcov_area = kcov->area; Patches currently in stable-queue which might be from dvyukov@google.com are queue-4.9/kvm-x86-fix-escape-of-guest-dr6-to-the-host.patch queue-4.9/blktrace-fix-unlocked-registration-of-tracepoints.patch queue-4.9/netfilter-x_tables-fix-int-overflow-in-xt_alloc_table_info.patch queue-4.9/netfilter-ipt_clusterip-fix-out-of-bounds-accesses-in-clusterip_tg_check.patch queue-4.9/kcov-detect-double-association-with-a-single-task.patch