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 purpose specific kcalloc() function instead of the argument
size * count 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 <[email protected]>
---
drivers/i3c/master/mipi-i3c-hci/hci.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h
index 80beb1d5be8f..f109923f6c3f 100644
--- a/drivers/i3c/master/mipi-i3c-hci/hci.h
+++ b/drivers/i3c/master/mipi-i3c-hci/hci.h
@@ -98,7 +98,7 @@ struct hci_xfer {
static inline struct hci_xfer *hci_alloc_xfer(unsigned int n)
{
- return kzalloc(sizeof(struct hci_xfer) * n, GFP_KERNEL);
+ return kcalloc(n, sizeof(struct hci_xfer), GFP_KERNEL);
}
static inline void hci_free_xfer(struct hci_xfer *xfer, unsigned int n)
--
2.25.1
On Sun, 12 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 purpose specific kcalloc() function instead of the argument
> size * count 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 <[email protected]>
Acked-by: Nicolas Pitre <[email protected]>
> ---
> drivers/i3c/master/mipi-i3c-hci/hci.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h
> index 80beb1d5be8f..f109923f6c3f 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/hci.h
> +++ b/drivers/i3c/master/mipi-i3c-hci/hci.h
> @@ -98,7 +98,7 @@ struct hci_xfer {
>
> static inline struct hci_xfer *hci_alloc_xfer(unsigned int n)
> {
> - return kzalloc(sizeof(struct hci_xfer) * n, GFP_KERNEL);
> + return kcalloc(n, sizeof(struct hci_xfer), GFP_KERNEL);
> }
>
> static inline void hci_free_xfer(struct hci_xfer *xfer, unsigned int n)
> --
> 2.25.1
>
>
On Sun, 12 Sep 2021 17:51:35 +0200, 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.
>
> [...]
Applied, thanks!
[1/1] i3c/master/mipi-i3c-hci: Prefer kcalloc over open coded arithmetic
commit: 41a0430dd5ca65afdecf10fb0b8b56966a1c5d04
Best regards,
--
Alexandre Belloni <[email protected]>