From 50740d5de6145cb88e69ccb29c586f10c401e3ee Mon Sep 17 00:00:00 2001 From: Len Baker Date: Sat, 18 Sep 2021 12:40:55 +0200 Subject: dmaengine: pxa_dma: Prefer struct_size over open coded arithmetic As noted in the "Deprecated Interfaces, Language Features, Attributes, and Conventions" documentation [1], size calculations (especially multiplication) should not be performed in memory allocator (or similar) function arguments due to the risk of them overflowing. This could lead to values wrapping around and a smaller allocation being made than the caller was expecting. Using those allocations could lead to linear overflows of heap memory and other misbehaviors. So, use the struct_size() helper to do the arithmetic instead of the argument "size + count * size" in the kzalloc() function. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments Signed-off-by: Len Baker Reviewed-by: Gustavo A. R. Silva Signed-off-by: Gustavo A. R. Silva --- drivers/dma/pxa_dma.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/dma/pxa_dma.c') diff --git a/drivers/dma/pxa_dma.c b/drivers/dma/pxa_dma.c index 4a2a796e348c..52d04641e361 100644 --- a/drivers/dma/pxa_dma.c +++ b/drivers/dma/pxa_dma.c @@ -742,8 +742,7 @@ pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc) dma_addr_t dma; int i; - sw_desc = kzalloc(sizeof(*sw_desc) + - nb_hw_desc * sizeof(struct pxad_desc_hw *), + sw_desc = kzalloc(struct_size(sw_desc, hw_desc, nb_hw_desc), GFP_NOWAIT); if (!sw_desc) return NULL; -- cgit v1.2.3-58-ga151