linux/sound/core/seq
Takashi Iwai 13d5e5d472 ALSA: seq: Fix double port list deletion
The commit [7f0973e973cd: ALSA: seq: Fix lockdep warnings due to
double mutex locks] split the management of two linked lists (source
and destination) into two individual calls for avoiding the AB/BA
deadlock.  However, this may leave the possible double deletion of one
of two lists when the counterpart is being deleted concurrently.
It ends up with a list corruption, as revealed by syzkaller fuzzer.

This patch fixes it by checking the list emptiness and skipping the
deletion and the following process.

BugLink: http://lkml.kernel.org/r/CACT4Y+bay9qsrz6dQu31EcGaH9XwfW7o3oBzSQUG9fMszoh=Sg@mail.gmail.com
Fixes: 7f0973e973 ('ALSA: seq: Fix lockdep warnings due to 'double mutex locks)
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-02-16 14:37:19 +01:00
..
oss ALSA: seq: Degrade the error message for too many opens 2016-01-25 11:52:23 +01:00
Kconfig ALSA: clean up the logic for building sequencer modules 2009-05-29 11:49:42 +02:00
Makefile ALSA: core: Fix randconfig build wrt CONFIG_PROC_FS 2015-05-29 07:21:02 +02:00
seq.c Subject: ALSA: seq: Remove autoload locks in driver registration 2014-10-18 20:25:19 +02:00
seq_clientmgr.c ALSA: seq: Fix lockdep warnings due to double mutex locks 2016-02-03 14:51:51 +01:00
seq_clientmgr.h [ALSA] sound/core/seq: move declarations of globally visible variables to proper headers 2008-01-31 17:29:35 +01:00
seq_compat.c ALSA: seq: Fix snd_seq_call_port_info_ioctl in compat mode 2016-01-18 14:39:13 +01:00
seq_device.c ALSA: core: Fix randconfig build wrt CONFIG_PROC_FS 2015-05-29 07:21:02 +02:00
seq_dummy.c ALSA: seq: Drop snd_seq_autoload_lock() and _unlock() 2015-02-12 14:42:31 +01:00
seq_fifo.c ALSA: seq: Drop superfluous error/debug messages after malloc failures 2015-03-10 15:41:18 +01:00
seq_fifo.h [ALSA] Remove xxx_t typedefs: Sequencer 2006-01-03 12:17:52 +01:00
seq_info.c ALSA: core: Build conditionally and remove superfluous ifdefs 2015-04-24 17:31:07 +02:00
seq_info.h ALSA: replace CONFIG_PROC_FS with CONFIG_SND_PROC_FS 2015-05-27 21:25:19 +02:00
seq_lock.c ALSA: seq: Use standard printk helpers 2014-02-14 08:14:18 +01:00
seq_lock.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
seq_memory.c ALSA: seq: Fix leak of pool buffer at concurrent writes 2016-02-15 16:26:52 +01:00
seq_memory.h ALSA: core: sparse cleanups 2011-02-14 17:10:11 +01:00
seq_midi.c ALSA: seq: Drop snd_seq_autoload_lock() and _unlock() 2015-02-12 14:42:31 +01:00
seq_midi_emul.c ALSA: seq: potential out of bounds in do_control() 2015-02-12 11:07:48 +01:00
seq_midi_event.c sound: Add module.h to the previously silent sound users 2011-10-31 19:31:21 -04:00
seq_ports.c ALSA: seq: Fix double port list deletion 2016-02-16 14:37:19 +01:00
seq_ports.h ALSA: seq: remove unused callback_all field 2015-01-26 13:56:58 +01:00
seq_prioq.c ALSA: seq: Drop superfluous error/debug messages after malloc failures 2015-03-10 15:41:18 +01:00
seq_prioq.h [ALSA] Remove xxx_t typedefs: Sequencer 2006-01-03 12:17:52 +01:00
seq_queue.c ALSA: seq: Fix race at timer setup and close 2016-01-12 17:50:41 +01:00
seq_queue.h [ALSA] semaphore -> mutex (core part) 2006-03-22 10:24:50 +01:00
seq_system.c sound: Add export.h for THIS_MODULE/EXPORT_SYMBOL where needed 2011-10-31 19:31:22 -04:00
seq_system.h [ALSA] Remove xxx_t typedefs: Sequencer 2006-01-03 12:17:52 +01:00
seq_timer.c ALSA: seq: Fix yet another races among ALSA timer accesses 2016-02-01 12:23:29 +01:00
seq_timer.h [ALSA] sound/core/seq: move declarations of globally visible variables to proper headers 2008-01-31 17:29:35 +01:00
seq_virmidi.c ALSA: rawmidi: Make snd_rawmidi_transmit() race-free 2016-02-03 14:51:28 +01:00