ALSA: gus: fix null pointer dereference on pointer block

The pointer block return from snd_gf1_dma_next_block could be
null, so there is a potential null pointer dereference issue.
Fix this by adding a null check before dereference.

Signed-off-by: Chengfeng Ye <cyeaa@connect.ust.hk>
Link: https://lore.kernel.org/r/20211024104611.9919-1-cyeaa@connect.ust.hk
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Chengfeng Ye 2021-10-24 03:46:11 -07:00 committed by Takashi Iwai
parent f917c04fac
commit a0d21bb327

View File

@ -126,6 +126,8 @@ static void snd_gf1_dma_interrupt(struct snd_gus_card * gus)
}
block = snd_gf1_dma_next_block(gus);
spin_unlock(&gus->dma_lock);
if (!block)
return;
snd_gf1_dma_program(gus, block->addr, block->buf_addr, block->count, (unsigned short) block->cmd);
kfree(block);
#if 0