Messages in this thread | | | Date | Mon, 6 Sep 2021 00:30:16 -0400 (EDT) | From | Nicolas Pitre <> | Subject | Re: [PATCH] i3c/master/mipi-i3c-hci: Prefer struct_size over open coded arithmetic |
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On Sun, 5 Sep 2021, Len Baker wrote:
> 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 <len.baker@gmx.com>
Acked-by: Nicolas Pitre <npitre@baylibre.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; > -- > 2.25.1 > >
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