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authorTakashi Iwai <tiwai@suse.de>2020-12-18 17:56:24 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-07-29 18:06:51 +0300
commit19241a56c5d6e74b32b1fbb1bd3ba7edef421f16 (patch)
treee31090675ab7104d29ac7c02f76c1cf9754f048c /sound
parent7ab60de3d88881a31fd8d7953cb801d4fad63921 (diff)
downloadlinux-19241a56c5d6e74b32b1fbb1bd3ba7edef421f16.tar.xz
ALSA: memalloc: Align buffer allocations in page size
commit 5c1733e33c888a3cb7f576564d8ad543d5ad4a9e upstream. Currently the standard memory allocator (snd_dma_malloc_pages*()) passes the byte size to allocate as is. Most of the backends allocates real pages, hence the actual allocations are aligned in page size. However, the genalloc doesn't seem assuring the size alignment, hence it may result in the access outside the buffer when the whole memory pages are exposed via mmap. For avoiding such inconsistencies, this patch makes the allocation size always to be aligned in page size. Note that, after this change, snd_dma_buffer.bytes field contains the aligned size, not the originally requested size. This value is also used for releasing the pages in return. Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> Link: https://lore.kernel.org/r/20201218145625.2045-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound')
-rw-r--r--sound/core/memalloc.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
index 753d5fc4b284..81a171668f42 100644
--- a/sound/core/memalloc.c
+++ b/sound/core/memalloc.c
@@ -179,6 +179,7 @@ int snd_dma_alloc_pages(int type, struct device *device, size_t size,
if (WARN_ON(!dmab))
return -ENXIO;
+ size = PAGE_ALIGN(size);
dmab->dev.type = type;
dmab->dev.dev = device;
dmab->bytes = 0;