From f96b2e77f6d1b0c5181e0eae3dc60a00a5cd692a Mon Sep 17 00:00:00 2001 From: Len Baker Date: Sun, 5 Sep 2021 16:40:54 +0200 Subject: [PATCH] i3c/master/mipi-i3c-hci: 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/v5.14/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments Signed-off-by: Len Baker Acked-by: Nicolas Pitre Signed-off-by: Alexandre Belloni Link: https://lore.kernel.org/r/20210905144054.5124-1-len.baker@gmx.com --- drivers/i3c/master/mipi-i3c-hci/dma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index af873a9be050..2990ac9eaade 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -223,7 +223,7 @@ static int hci_dma_init(struct i3c_hci *hci) } if (nr_rings > XFER_RINGS) nr_rings = XFER_RINGS; - rings = kzalloc(sizeof(*rings) + nr_rings * sizeof(*rh), GFP_KERNEL); + rings = kzalloc(struct_size(rings, headers, nr_rings), GFP_KERNEL); if (!rings) return -ENOMEM; hci->io_data = rings;