ALSA: ak4114: Fix wrong register array size

The size of the register cache array is actually 6 instead of 7,
as it caches up to AK4114_REG_INT1_MASK.  This resulted in unexpected
access out of array range, although most of them aren't so serious
(just reading one more byte on the stack at snd_ak4114_create()).

Also, the check of cache size was wrongly done by checking with
sizeof() instead of ARRAY_SIZE().  Fixed this together.

(And yes, hardcoded numbers are bad, but I keep the coding style as is
 for making it clear what this patch actually does.)

Spotted by coverity among several CIDs, e.g. 711621.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/include/sound/ak4114.h b/include/sound/ak4114.h
index 3ce69fd..52f02a6 100644 (file)
--- a/include/sound/ak4114.h
+++ b/include/sound/ak4114.h
@@ -170,7 +170,7 @@ struct ak4114 {
        void * private_data;
        unsigned int init: 1;
        spinlock_t lock;
-       unsigned char regmap[7];
+       unsigned char regmap[6];
        unsigned char txcsb[5];
        struct snd_kcontrol *kctls[AK4114_CONTROLS];
        struct snd_pcm_substream *playback_substream;
@@ -189,7 +189,7 @@ struct ak4114 {
 
 int snd_ak4114_create(struct snd_card *card,
                      ak4114_read_t *read, ak4114_write_t *write,
-                     const unsigned char pgm[7], const unsigned char txcsb[5],
+                     const unsigned char pgm[6], const unsigned char txcsb[5],
                      void *private_data, struct ak4114 **r_ak4114);
 void snd_ak4114_reg_write(struct ak4114 *ak4114, unsigned char reg, unsigned char mask, unsigned char val);
 void snd_ak4114_reinit(struct ak4114 *ak4114);

diff --git a/sound/i2c/other/ak4114.c b/sound/i2c/other/ak4114.c
index 5bf4fca..15ae025 100644 (file)
--- a/sound/i2c/other/ak4114.c
+++ b/sound/i2c/other/ak4114.c
@@ -60,7 +60,7 @@ static void reg_dump(struct ak4114 *ak4114)
 
        printk(KERN_DEBUG "AK4114 REG DUMP:\n");
        for (i = 0; i < 0x20; i++)
-               printk(KERN_DEBUG "reg[%02x] = %02x (%02x)\n", i, reg_read(ak4114, i), i < sizeof(ak4114->regmap) ? ak4114->regmap[i] : 0);
+               printk(KERN_DEBUG "reg[%02x] = %02x (%02x)\n", i, reg_read(ak4114, i), i < ARRAY_SIZE(ak4114->regmap) ? ak4114->regmap[i] : 0);
 }
 #endif
 
@@ -81,7 +81,7 @@ static int snd_ak4114_dev_free(struct snd_device *device)
 
 int snd_ak4114_create(struct snd_card *card,
                      ak4114_read_t *read, ak4114_write_t *write,
-                     const unsigned char pgm[7], const unsigned char txcsb[5],
+                     const unsigned char pgm[6], const unsigned char txcsb[5],
                      void *private_data, struct ak4114 **r_ak4114)
 {
        struct ak4114 *chip;
@@ -101,7 +101,7 @@ int snd_ak4114_create(struct snd_card *card,
        chip->private_data = private_data;
        INIT_DELAYED_WORK(&chip->work, ak4114_stats);
 
-       for (reg = 0; reg < 7; reg++)
+       for (reg = 0; reg < 6; reg++)
                chip->regmap[reg] = pgm[reg];
        for (reg = 0; reg < 5; reg++)
                chip->txcsb[reg] = txcsb[reg];
@@ -142,7 +142,7 @@ static void ak4114_init_regs(struct ak4114 *chip)
        /* release reset, but leave powerdown */
        reg_write(chip, AK4114_REG_PWRDN, (old | AK4114_RST) & ~AK4114_PWN);
        udelay(200);
-       for (reg = 1; reg < 7; reg++)
+       for (reg = 1; reg < 6; reg++)
                reg_write(chip, reg, chip->regmap[reg]);
        for (reg = 0; reg < 5; reg++)
                reg_write(chip, reg + AK4114_REG_TXCSB0, chip->txcsb[reg]);