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authorJohannes Weiner <hannes@cmpxchg.org>2009-01-06 22:43:10 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-06 23:59:31 (GMT)
commit58c6d3dfe436eb8cfb451981d8fdc9044eaf42da (patch)
treec4f7fd8f6a24c5d242dd7bd0a876413f15e26fcd /kernel/dma-coherent.c
parenteccd83e116e7f414a1da3aae3745384b7b171883 (diff)
downloadlinux-fsl-qoriq-58c6d3dfe436eb8cfb451981d8fdc9044eaf42da.tar.xz
dma-coherent: catch oversized requests to dma_alloc_from_coherent()
Prevent passing an order to bitmap_find_free_region() that is larger than the actual bitmap can represent. These requests can come from device drivers that have no idea how big the dma region is and need to rely on dma_alloc_from_coherent() to sort it out for them. Reported-by: Guennadi Liakhovetski <lg@denx.de> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Dmitry Baryshkov <dbaryshkov@gmail.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/dma-coherent.c')
-rw-r--r--kernel/dma-coherent.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/dma-coherent.c b/kernel/dma-coherent.c
index 8056d08..0387074 100644
--- a/kernel/dma-coherent.c
+++ b/kernel/dma-coherent.c
@@ -118,6 +118,8 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size,
mem = dev->dma_mem;
if (!mem)
return 0;
+ if (unlikely(size > mem->size))
+ return 0;
pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);
if (pageno >= 0) {