[PATCH v2 1/7] ALSA: als100: fix format string overflow warning

From: Arnd Bergmann
Date: Tue Jul 18 2017 - 07:49:46 EST


The compiler sees that the format string might overflow for the longname:

sound/isa/als100.c: In function 'snd_als100_pnp_detect':
sound/isa/als100.c:225:27: error: ', dma ' directive writing 6 bytes into a region of size between 0 and 64 [-Werror=format-overflow=]
sprintf(card->longname, "%s, %s at 0x%lx, irq %d, dma %d",
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sound/isa/als100.c:225:3: note: 'sprintf' output between 24 and 113 bytes into a destination of size 80
sprintf(card->longname, "%s, %s at 0x%lx, irq %d, dma %d",

Open-coding "shortname" here gets us below the limit, and using
snprintf() is a good idea too.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
sound/isa/als100.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/sound/isa/als100.c b/sound/isa/als100.c
index bc9ea306ee02..6a2c5b48f3ae 100644
--- a/sound/isa/als100.c
+++ b/sound/isa/als100.c
@@ -222,15 +222,16 @@ static int snd_card_als100_probe(int dev,
if (pid->driver_data == SB_HW_DT019X) {
strcpy(card->driver, "DT-019X");
strcpy(card->shortname, "Diamond Tech. DT-019X");
- sprintf(card->longname, "%s, %s at 0x%lx, irq %d, dma %d",
- card->shortname, chip->name, chip->port,
- irq[dev], dma8[dev]);
+ snprintf(card->longname, sizeof(card->longname),
+ "Diamond Tech. DT-019X, %s at 0x%lx, irq %d, dma %d",
+ chip->name, chip->port, irq[dev], dma8[dev]);
} else {
strcpy(card->driver, "ALS100");
strcpy(card->shortname, "Avance Logic ALS100");
- sprintf(card->longname, "%s, %s at 0x%lx, irq %d, dma %d&%d",
- card->shortname, chip->name, chip->port,
- irq[dev], dma8[dev], dma16[dev]);
+ snprintf(card->longname, sizeof(card->longname),
+ "Avance Logic ALS100, %s at 0x%lx, irq %d, dma %d&%d",
+ chip->name, chip->port, irq[dev], dma8[dev],
+ dma16[dev]);
}

if ((error = snd_sb16dsp_pcm(chip, 0)) < 0) {
--
2.9.0