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Subject[PATCH] swiotlb: avoid potential left shift overflow
Date
The second operand passed to slot_addr() is declared as int or unsigned int
in all call sites. The left-shift to get the offset of a slot can overflow
if swiotlb size is larger than 4G.

Fixes: 26a7e094783d ("swiotlb: refactor swiotlb_tbl_map_single")
Signed-off-by: Chao Gao <chao.gao@intel.com>
---
kernel/dma/swiotlb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index c5a9190b218f..391b03b72978 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -579,7 +579,7 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size
}
}

-#define slot_addr(start, idx) ((start) + ((idx) << IO_TLB_SHIFT))
+#define slot_addr(start, idx) ((start) + ((phys_addr_t)(idx) << IO_TLB_SHIFT))

/*
* Carefully handle integer overflow which can occur when boundary_mask == ~0UL.
--
2.25.1
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