Re: [PATCH] ipv4: fib: Fix fib_info_hash_alloc() allocation type

[David Ahern <dsahern@kernel.org>]

On 4/25/25 11:05 PM, Kees Cook wrote:
> In preparation for making the kmalloc family of allocators type aware,
> we need to make sure that the returned type from the allocation matches
> the type of the variable being assigned. (Before, the allocator would
> always return "void *", which can be implicitly cast to any pointer type.)
> 
> This was allocating many sizeof(struct hlist_head *) when it actually
> wanted sizeof(struct hlist_head). Luckily these are the same size.
> Adjust the allocation type to match the assignment.
> 
> Signed-off-by: Kees Cook <kees@kernel.org>
> ---
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: David Ahern <dsahern@kernel.org>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: Simon Horman <horms@kernel.org>
> Cc: <netdev@vger.kernel.org>
> ---
>  net/ipv4/fib_semantics.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
> index f68bb9e34c34..37d12b0bc6be 100644
> --- a/net/ipv4/fib_semantics.c
> +++ b/net/ipv4/fib_semantics.c
> @@ -365,7 +365,7 @@ static struct hlist_head *fib_info_laddrhash_bucket(const struct net *net,
>  static struct hlist_head *fib_info_hash_alloc(unsigned int hash_bits)
>  {
>  	/* The second half is used for prefsrc */
> -	return kvcalloc((1 << hash_bits) * 2, sizeof(struct hlist_head *),
> +	return kvcalloc((1 << hash_bits) * 2, sizeof(struct hlist_head),
>  			GFP_KERNEL);
>  }
>  

Reviewed-by: David Ahern <dsahern@kernel.org>

Fixes: fa336adc100e ("ipv4: fib: Allocate fib_info_hash[] and
fib_info_laddrhash[] by kvcalloc().)