The patch titled
dma-coherent: catch oversized requests to dma_alloc_from_coherent()
has been added to the -mm tree. Its filename is
dma-coherent-catch-oversized-requests-to-dma_alloc_from_coherent.patch
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------------------------------------------------------
Subject: dma-coherent: catch oversized requests to dma_alloc_from_coherent()
From: Johannes Weiner <hannes@xxxxxxxxxxx>
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@xxxxxxx>
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
Cc: Dmitry Baryshkov <dbaryshkov@xxxxxxxxx>
Cc: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/dma-coherent.c | 2 ++
1 file changed, 2 insertions(+)
diff -puN kernel/dma-coherent.c~dma-coherent-catch-oversized-requests-to-dma_alloc_from_coherent kernel/dma-coherent.c
--- a/kernel/dma-coherent.c~dma-coherent-catch-oversized-requests-to-dma_alloc_from_coherent
+++ a/kernel/dma-coherent.c
@@ -118,6 +118,8 @@ int dma_alloc_from_coherent(struct devic
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) {
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
mm-more-likely-reclaim-madv_sequential-mappings.patch
mm-apply_to_range-call-pte-function-with-lazy-updates.patch
vmscan-shrink_active_list-reduce-lru_lock-hold-time.patch
dma_alloc_coherent-clean-it-up.patch
dma-coherent-catch-oversized-requests-to-dma_alloc_from_coherent.patch
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