[PATCH] sound: hdmi: avoid dereferencing uninitialized 'jack' pointer

Takashi Iwai
2016-02-16T15:49:42Z

On Tue, 16 Feb 2016 15:47:28 +0100,
Arnd Bergmann wrote:
>
> When CONFIG_SND_JACK is disabled, the hdmi driver tries to create
> a new output jack structure and dereferences it even though
> the pointer is never assigned:
>
> sound/pci/hda/patch_hdmi.c: In function 'generic_hdmi_build_jack':
> sound/pci/hda/patch_hdmi.c:2534:30: error: 'jack' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> sound/pci/hda/patch_hdmi.c:2526:19: note: 'jack' was declared here
>
> This uses a compile-time check to avoid calling a nonworking
> snd_jack_new() function, and sets an explicit NULL pointer instead.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Fixes: 788d441a164c ("ALSA: hda - Use component ops for i915 HDMI/DP audio jack handling")

Thanks for the patch. But I think it's cleaner to fix Kconfig.

Thinking more of it, maybe splitting jack stuff as a separate module
and does reverse-select to CONFIG_INPUT would be better. Then its
users can select simply SND_JACK, and everything would fit.

An untested patch is below. Mark, what do you think?

Takashi

---
diff --git a/sound/core/Kconfig b/sound/core/Kconfig
index a2a1e24becc6..cf4058dde959 100644
--- a/sound/core/Kconfig
+++ b/sound/core/Kconfig
@@ -24,11 +24,9 @@ config SND_RAWMIDI
config SND_COMPRESS_OFFLOAD
tristate

-# To be effective this also requires INPUT - users should say:
-# select SND_JACK if INPUT=y || INPUT=SND
-# to avoid having to force INPUT on.
config SND_JACK
- bool
+ tristate
+ select INPUT

config SND_SEQUENCER
tristate "Sequencer support"
diff --git a/sound/core/Makefile b/sound/core/Makefile
index 48ab4b8f8279..d16e2b0ba4fb 100644
--- a/sound/core/Makefile
+++ b/sound/core/Makefile
@@ -11,7 +11,8 @@ endif
snd-$(CONFIG_ISA_DMA_API) += isadma.o
snd-$(CONFIG_SND_OSSEMUL) += sound_oss.o
snd-$(CONFIG_SND_VMASTER) += vmaster.o
-snd-$(CONFIG_SND_JACK) += ctljack.o jack.o
+
+snd-jack-objs := ctljack.o jack.o

snd-pcm-y := pcm.o pcm_native.o pcm_lib.o pcm_misc.o \
pcm_memory.o memalloc.o
@@ -41,6 +42,7 @@ obj-$(CONFIG_SND_RTCTIMER) += snd-rtctimer.o
obj-$(CONFIG_SND_PCM) += snd-pcm.o
obj-$(CONFIG_SND_DMAENGINE_PCM) += snd-pcm-dmaengine.o
obj-$(CONFIG_SND_RAWMIDI) += snd-rawmidi.o
+obj-$(CONFIG_SND_JACK) += snd-jack.o

obj-$(CONFIG_SND_OSSEMUL) += oss/
obj-$(CONFIG_SND_SEQUENCER) += seq/
diff --git a/sound/pci/Kconfig b/sound/pci/Kconfig
index 8f6594a7d37f..32151d8c6bb8 100644
--- a/sound/pci/Kconfig
+++ b/sound/pci/Kconfig
@@ -866,7 +866,7 @@ config SND_VIRTUOSO
select SND_OXYGEN_LIB
select SND_PCM
select SND_MPU401_UART
- select SND_JACK if INPUT=y || INPUT=SND
+ select SND_JACK
help
Say Y here to include support for sound cards based on the
Asus AV66/AV100/AV200 chips, i.e., Xonar D1, DX, D2, D2X, DS, DSX,
diff --git a/sound/pci/hda/Kconfig b/sound/pci/hda/Kconfig
index e94cfd5c69f7..bb02c2d48fd5 100644
--- a/sound/pci/hda/Kconfig
+++ b/sound/pci/hda/Kconfig
@@ -4,7 +4,7 @@ config SND_HDA
tristate
select SND_PCM
select SND_VMASTER
- select SND_JACK if INPUT=y || INPUT=SND
+ select SND_JACK
select SND_HDA_CORE

config SND_HDA_INTEL
diff --git a/sound/soc/Kconfig b/sound/soc/Kconfig
index 7ea66ee3653f..182d92efc7c8 100644
--- a/sound/soc/Kconfig
+++ b/sound/soc/Kconfig
@@ -6,7 +6,7 @@ menuconfig SND_SOC
tristate "ALSA for SoC audio support"
select SND_PCM
select AC97_BUS if SND_SOC_AC97_BUS
- select SND_JACK if INPUT=y || INPUT=SND
+ select SND_JACK
select REGMAP_I2C if I2C
select REGMAP_SPI if SPI_MASTER
---help---