From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754062AbdCPPXo (ORCPT ); Thu, 16 Mar 2017 11:23:44 -0400 Received: from terminus.zytor.com ([65.50.211.136]:55034 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751763AbdCPPVz (ORCPT ); Thu, 16 Mar 2017 11:21:55 -0400 Date: Thu, 16 Mar 2017 08:19:57 -0700 From: tip-bot for Peter Zijlstra Message-ID: Cc: tglx@linutronix.de, alexander.shishkin@linux.intel.com, hpa@zytor.com, mingo@kernel.org, eranian@google.com, jolsa@redhat.com, dvyukov@google.com, mathieu.desnoyers@efficios.com, peterz@infradead.org, acme@redhat.com, linux-kernel@vger.kernel.org, oleg@redhat.com, fweisbec@gmail.com, vincent.weaver@maine.edu, torvalds@linux-foundation.org, acme@kernel.org Reply-To: acme@redhat.com, oleg@redhat.com, linux-kernel@vger.kernel.org, fweisbec@gmail.com, vincent.weaver@maine.edu, acme@kernel.org, torvalds@linux-foundation.org, eranian@google.com, jolsa@redhat.com, mathieu.desnoyers@efficios.com, dvyukov@google.com, peterz@infradead.org, tglx@linutronix.de, alexander.shishkin@linux.intel.com, hpa@zytor.com, mingo@kernel.org In-Reply-To: <20170316125823.190342547@infradead.org> References: <20170316125823.190342547@infradead.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf/core: Fix event inheritance on fork() Git-Commit-ID: e7cc4865f0f31698ef2f7aac01a50e78968985b7 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: e7cc4865f0f31698ef2f7aac01a50e78968985b7 Gitweb: http://git.kernel.org/tip/e7cc4865f0f31698ef2f7aac01a50e78968985b7 Author: Peter Zijlstra AuthorDate: Thu, 16 Mar 2017 13:47:49 +0100 Committer: Ingo Molnar CommitDate: Thu, 16 Mar 2017 14:16:52 +0100 perf/core: Fix event inheritance on fork() While hunting for clues to a use-after-free, Oleg spotted that perf_event_init_context() can loose an error value with the result that fork() can succeed even though we did not fully inherit the perf event context. Spotted-by: Oleg Nesterov Signed-off-by: Peter Zijlstra (Intel) Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Dmitry Vyukov Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Linus Torvalds Cc: Mathieu Desnoyers Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Cc: oleg@redhat.com Cc: stable@vger.kernel.org Fixes: 889ff0150661 ("perf/core: Split context's event group list into pinned and non-pinned lists") Link: http://lkml.kernel.org/r/20170316125823.190342547@infradead.org Signed-off-by: Ingo Molnar --- kernel/events/core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 4742909..fc7c9a8 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -10679,7 +10679,7 @@ static int perf_event_init_context(struct task_struct *child, int ctxn) ret = inherit_task_group(event, parent, parent_ctx, child, ctxn, &inherited_all); if (ret) - break; + goto out_unlock; } /* @@ -10695,7 +10695,7 @@ static int perf_event_init_context(struct task_struct *child, int ctxn) ret = inherit_task_group(event, parent, parent_ctx, child, ctxn, &inherited_all); if (ret) - break; + goto out_unlock; } raw_spin_lock_irqsave(&parent_ctx->lock, flags); @@ -10723,6 +10723,7 @@ static int perf_event_init_context(struct task_struct *child, int ctxn) } raw_spin_unlock_irqrestore(&parent_ctx->lock, flags); +out_unlock: mutex_unlock(&parent_ctx->mutex); perf_unpin_context(parent_ctx);