ALSA: emu10k1: Avoid access to invalid pages when period=1
When period=1, the driver tries to allocate a bit bigger buffer than
requested by the user due to the irq latency tolerance. This may lead
to accesses over the actually allocated pages.
This patch adds a check of the page index and assigns the silent page
when it's over the given buffer size.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/emu10k1/memory.c b/sound/pci/emu10k1/memory.c
index 4f502a2..0a43662 100644
--- a/sound/pci/emu10k1/memory.c
+++ b/sound/pci/emu10k1/memory.c
@@ -326,7 +326,10 @@
for (page = blk->first_page; page <= blk->last_page; page++, idx++) {
unsigned long ofs = idx << PAGE_SHIFT;
dma_addr_t addr;
- addr = snd_pcm_sgbuf_get_addr(substream, ofs);
+ if (ofs >= runtime->dma_bytes)
+ addr = emu->silent_page.addr;
+ else
+ addr = snd_pcm_sgbuf_get_addr(substream, ofs);
if (! is_valid_page(emu, addr)) {
printk(KERN_ERR "emu: failure page = %d\n", idx);
mutex_unlock(&hdr->block_mutex);