linux/sound/core
Takashi Iwai 8d218dd811 ALSA: seq: oss: Hardening for potential Spectre v1
As Smatch recently suggested, a few places in OSS sequencer codes may
expand the array directly from the user-space value with speculation,
namely there are a significant amount of references to either
info->ch[] or dp->synths[] array:

  sound/core/seq/oss/seq_oss_event.c:315 note_on_event() warn: potential spectre issue 'info->ch' (local cap)
  sound/core/seq/oss/seq_oss_event.c:362 note_off_event() warn: potential spectre issue 'info->ch' (local cap)
  sound/core/seq/oss/seq_oss_synth.c:470 snd_seq_oss_synth_load_patch() warn: potential spectre issue 'dp->synths' (local cap)
  sound/core/seq/oss/seq_oss_event.c:293 note_on_event() warn: potential spectre issue 'dp->synths'
  sound/core/seq/oss/seq_oss_event.c:353 note_off_event() warn: potential spectre issue 'dp->synths'
  sound/core/seq/oss/seq_oss_synth.c:506 snd_seq_oss_synth_sysex() warn: potential spectre issue 'dp->synths'
  sound/core/seq/oss/seq_oss_synth.c:580 snd_seq_oss_synth_ioctl() warn: potential spectre issue 'dp->synths'

Although all these seem doing only the first load without further
reference, we may want to stay in a safer side, so hardening with
array_index_nospec() would still make sense.

We may put array_index_nospec() at each place, but here we take a
different approach:

- For dp->synths[], change the helpers to retrieve seq_oss_synthinfo
  pointer directly instead of the array expansion at each place

- For info->ch[], harden in a normal way, as there are only a couple
  of places

As a result, the existing helper, snd_seq_oss_synth_is_valid() is
replaced with snd_seq_oss_synth_info().  Also, we cover MIDI device
where a similar array expansion is done, too, although it wasn't
reported by Smatch.

BugLink: https://marc.info/?l=linux-kernel&m=152411496503418&w=2
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-25 10:37:45 +02:00
..
oss ALSA: pcm: Fix endless loop for XRUN recovery in OSS emulation 2018-04-07 13:10:11 +02:00
seq ALSA: seq: oss: Hardening for potential Spectre v1 2018-04-25 10:37:45 +02:00
compress_offload.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
control_compat.c ALSA: Get rid of card power_lock 2017-08-30 20:44:29 +02:00
control.c ALSA: control: Fix missing __user annotation 2018-04-23 16:19:52 +02:00
ctljack.c ALSA: declare snd_kcontrol_new structures as const 2017-05-30 10:29:25 +02:00
device.c ALSA: core: Use %pS printk format for direct addresses 2017-09-07 10:36:02 +02:00
hrtimer.c Merge branch 'for-next' into for-linus 2017-11-13 15:43:13 +01:00
hwdep_compat.c [PATCH] hwdep_compat missed __user annotations 2006-10-10 15:37:21 -07:00
hwdep.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-31 09:25:20 -08:00
info_oss.c ALSA: core: Follow standard EXPORT_SYMBOL() declarations 2017-06-16 16:19:16 +02:00
info.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
init.c ALSA: Use scnprintf() instead of snprintf() for show 2018-02-27 09:16:52 +01:00
isadma.c ALSA: core: Follow standard EXPORT_SYMBOL() declarations 2017-06-16 16:19:16 +02:00
jack.c ALSA: fix kernel-doc build warning 2017-10-30 08:10:07 +01:00
Kconfig ALSA: seq: Allow the modular sequencer registration 2017-06-12 08:43:33 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
memalloc.c ALSA: core: Follow standard EXPORT_SYMBOL() declarations 2017-06-16 16:19:16 +02:00
memory.c ALSA: core: Follow standard EXPORT_SYMBOL() declarations 2017-06-16 16:19:16 +02:00
misc.c ALSA: core: Follow standard EXPORT_SYMBOL() declarations 2017-06-16 16:19:16 +02:00
pcm_compat.c ALSA: pcm: Return negative delays from SNDRV_PCM_IOCTL_DELAY. 2018-04-23 08:41:35 +02:00
pcm_dmaengine.c ASoC: dmaengine_pcm: Add support for packed transfers 2016-04-27 17:34:11 +01:00
pcm_drm_eld.c ALSA: pcm: use helper function to refer parameter as read-only 2017-05-17 07:24:39 +02:00
pcm_iec958.c ALSA: pcm: Allow 32 bit sample format in IEC958 channel status helper 2016-04-06 14:33:38 -07:00
pcm_lib.c ALSA: pcm: Use krealloc() for resizing the rules array 2018-03-13 15:37:58 +01:00
pcm_local.h ALSA: pcm: unify codes to operate application-side position on PCM buffer 2017-06-12 08:49:22 +02:00
pcm_memory.c ALSA: pcm: Follow standard EXPORT_SYMBOL() declarations 2017-06-16 16:18:58 +02:00
pcm_misc.c ALSA: pcm: add SNDRV_PCM_FORMAT_{S,U}20 2017-11-29 09:26:33 +01:00
pcm_native.c ALSA: pcm: Change return type to vm_fault_t 2018-04-25 08:15:45 +02:00
pcm_param_trace.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pcm_timer.c ALSA: pcm: include pcm_local.h and remove some extraneous tabs 2017-05-30 18:04:47 +02:00
pcm_trace.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pcm.c ALSA: pcm: Fix UAF at PCM release via PCM timer access 2018-04-03 08:36:40 +02:00
rawmidi_compat.c ALSA: rawmidi: Fix missing input substream checks in compat ioctls 2018-04-19 18:16:15 +02:00
rawmidi.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
seq_device.c ALSA: seq: Cancel pending autoload work at unbinding device 2017-09-12 12:41:20 +02:00
sgbuf.c ALSA: core: Deletion of unnecessary checks before two function calls 2014-11-21 20:06:57 +01:00
sound_oss.c ALSA: core: Follow standard EXPORT_SYMBOL() declarations 2017-06-16 16:19:16 +02:00
sound.c ALSA: core: Follow standard EXPORT_SYMBOL() declarations 2017-06-16 16:19:16 +02:00
timer_compat.c ALSA: timer: Remove kernel warning at compat ioctl error paths 2017-11-21 16:36:11 +01:00
timer.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
vmaster.c ALSA: vmaster: Zero-clear ctl before calling slave get 2018-03-08 08:41:13 +01:00