Re: [PATCH mptcp-next v2 04/36] mptcp: use sock_kfree_s instead of kfree

[Matthieu Baerts <matttbe@kernel.org>]

Hi Geliang,

On 22/10/2024 11:14, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
> 
> The local address entries on the userspace_pm_local_addr_list are allocated
> by sock_kmalloc(). It's better to use sock_kfree_s() to free them, instead

Good catch! Do you mind developing a bit why "it is better to use
sock_kfree_s()"?

To me, it looks like a bug fix: we should use sock_kfree_s() to adjust
the allocated size. In this case, a 'Fixes' tag should be added, and
target mptcp-net. WDYT?

> of using kfree().
> 
> Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> ---
>  net/mptcp/pm_userspace.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
> index 00a7f9dd90cf..3fb5713cd988 100644
> --- a/net/mptcp/pm_userspace.c
> +++ b/net/mptcp/pm_userspace.c
> @@ -91,6 +91,7 @@ static int mptcp_userspace_pm_delete_local_addr(struct mptcp_sock *msk,
>  						struct mptcp_pm_addr_entry *addr)
>  {
>  	struct mptcp_pm_addr_entry *entry, *tmp;
> +	struct sock *sk = (struct sock *)msk;
>  
>  	mptcp_for_each_address_safe(msk, entry, tmp) {
>  		if (mptcp_addresses_equal(&entry->addr, &addr->addr, false)) {
> @@ -98,7 +99,7 @@ static int mptcp_userspace_pm_delete_local_addr(struct mptcp_sock *msk,
>  			 * be used multiple times (e.g. fullmesh mode).
>  			 */
>  			list_del_rcu(&entry->list);
> -			kfree(entry);
> +			sock_kfree_s(sk, entry, sizeof(*entry));
>  			msk->pm.local_addr_used--;
>  			return 0;
>  		}

Cheers,
Matt
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