[PATCH] ALSA: mts64: fix NULL pointer dereference

From: Sudip Mukherjee
Date: Mon Feb 29 2016 - 07:14:04 EST


While registering pardev, the irq_func was also registered. As a
result when we tried to probe for the card, an interrupt was generated
and in the ISR we tried to dereference private_data. But private_data
is still NULL as we have not yet done snd_mts64_create(). Lets probe
for the card after mts64 is created.

Reported-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
Fixes: 94a573500d48 ("ALSA: mts64: use new parport device model")
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@xxxxxxxxxxxxxxx>
---
sound/drivers/mts64.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/sound/drivers/mts64.c b/sound/drivers/mts64.c
index c76bd87..fd4d18d 100644
--- a/sound/drivers/mts64.c
+++ b/sound/drivers/mts64.c
@@ -964,11 +964,6 @@ static int snd_mts64_probe(struct platform_device *pdev)
err = -EIO;
goto free_pardev;
}
- err = mts64_probe(p);
- if (err) {
- err = -EIO;
- goto release_pardev;
- }

if ((err = snd_mts64_create(card, pardev, &mts)) < 0) {
snd_printd("Cannot create main component\n");
@@ -976,6 +971,12 @@ static int snd_mts64_probe(struct platform_device *pdev)
}
card->private_data = mts;
card->private_free = snd_mts64_card_private_free;
+
+ err = mts64_probe(p);
+ if (err) {
+ err = -EIO;
+ goto __err;
+ }

if ((err = snd_mts64_rawmidi_create(card)) < 0) {
snd_printd("Creating Rawmidi component failed\n");
--
1.9.1