[alsa-devel] [PATCH] ASoC: soc-cache: Fix memory overflow in LZO initialization

Dimitris Papastamos dp at opensource.wolfsonmicro.com
Mon Nov 29 12:43:33 CET 2010

The bitmap_zero() nbits argument was improperly set to reg_size
but the underlying buffer was bmp_size long.  This caused the memset
to zero past the end of the allocated buffer and into the kernel heap
causing strange kernel crashes sometimes by overwriting critical
kernel structures.

Signed-off-by: Dimitris Papastamos <dp at opensource.wolfsonmicro.com>
 sound/soc/soc-cache.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c
index 9b1ba33..5143984 100644
--- a/sound/soc/soc-cache.c
+++ b/sound/soc/soc-cache.c
@@ -1348,7 +1348,7 @@ static int snd_soc_lzo_cache_init(struct snd_soc_codec *codec)
 		ret = -ENOMEM;
 		goto err;
-	bitmap_zero(sync_bmp, reg_size);
+	bitmap_zero(sync_bmp, bmp_size);
 	/* allocate the lzo blocks and initialize them */
 	for (i = 0; i < blkcount; ++i) {

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