perf/core: Fix use-after-free bug

Dmitry reported a KASAN use-after-free on event->group_leader.

It turns out there's a hole in perf_remove_from_context() due to
event_function_call() not calling its function when the task
associated with the event is already dead.

In this case the event will have been detached from the task, but the
grouping will have been retained, such that group operations might
still work properly while there are live child events etc.

This does however mean that we can miss a perf_group_detach() call
when the group decomposes, this in turn can then lead to
use-after-free.

Fix it by explicitly doing the group detach if its still required.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org # v4.5+
Cc: syzkaller <syzkaller@googlegroups.com>
Fixes: 63b6da39bb38 ("perf: Fix perf_event_exit_task() race")
Link: http://lkml.kernel.org/r/20170126153955.GD6515@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

path: root/sound/soc/codecs/wl1273.h

/*
 * sound/soc/codec/wl1273.h
 *
 * ALSA SoC WL1273 codec driver
 *
 * Copyright (C) Nokia Corporation
 * Author: Matti Aaltonen <matti.j.aaltonen@nokia.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#ifndef __WL1273_CODEC_H__
#define __WL1273_CODEC_H__

int wl1273_get_format(struct snd_soc_codec *codec, unsigned int *fmt);

#endif	/* End of __WL1273_CODEC_H__ */