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authorLen Baker <len.baker@gmx.com>2021-09-18 13:40:55 +0300
committerGustavo A. R. Silva <gustavoars@kernel.org>2021-10-21 02:35:22 +0300
commit50740d5de6145cb88e69ccb29c586f10c401e3ee (patch)
tree78c3d1f42615fc31cfd75a3f98ac8a12cd1fd347
parent5dfbbb668af9038dfa9f280ff5835dfb9c796864 (diff)
downloadlinux-50740d5de6145cb88e69ccb29c586f10c401e3ee.tar.xz
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 <len.baker@gmx.com> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
-rw-r--r--drivers/dma/pxa_dma.c3
1 files changed, 1 insertions, 2 deletions
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;