linux/sound/pci/ac97
Takashi Iwai 7194eda1ba ALSA: ac97: Fix incorrect bit shift at AC97-SPSA control write
The function snd_ac97_put_spsa() gets the bit shift value from the
associated private_value, but it extracts too much; the current code
extracts 8 bit values in bits 8-15, but this is a combination of two
nibbles (bits 8-11 and bits 12-15) for left and right shifts.
Due to the incorrect bits extraction, the actual shift may go beyond
the 32bit value, as spotted recently by UBSAN check:
 UBSAN: Undefined behaviour in sound/pci/ac97/ac97_codec.c:836:7
 shift exponent 68 is too large for 32-bit type 'int'

This patch fixes the shift value extraction by masking the properly
with 0x0f instead of 0xff.

Reported-and-tested-by: Meelis Roos <mroos@linux.ee>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-11-23 18:09:22 +01:00
..
ac97_codec.c ALSA: ac97: Fix incorrect bit shift at AC97-SPSA control write 2018-11-23 18:09:22 +01:00
ac97_id.h
ac97_local.h ALSA: ac97: Fix ifdef CONFIG_PROC_FS 2015-05-29 07:52:43 +02:00
ac97_patch.c scripts/spelling.txt: add "swith" pattern and fix typo instances 2017-02-27 18:43:46 -08:00
ac97_patch.h
ac97_pcm.c
ac97_proc.c sound: Use octal not symbolic permissions 2018-05-28 11:27:20 +02:00
Makefile ALSA: ac97: Fix ifdef CONFIG_PROC_FS 2015-05-29 07:52:43 +02:00