sctp: sctp_sock_filter(): avoid list_entry() on possibly empty list

Use list_is_first() to check whether tsp->asoc matches the first
element of ep->asocs, as the list is not guaranteed to have an entry.

Fixes: 8f840e47f1 ("sctp: add the sctp_diag.c file")
Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://lore.kernel.org/r/20230208-sctp-filter-v2-1-6e1f4017f326@diag.uniroma1.it
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Pietro Borrello 2023-02-09 12:13:05 +00:00 committed by Jakub Kicinski
parent 0ed577e7e8
commit a1221703a0

View file

@ -343,11 +343,9 @@ static int sctp_sock_filter(struct sctp_endpoint *ep, struct sctp_transport *tsp
struct sctp_comm_param *commp = p;
struct sock *sk = ep->base.sk;
const struct inet_diag_req_v2 *r = commp->r;
struct sctp_association *assoc =
list_entry(ep->asocs.next, struct sctp_association, asocs);
/* find the ep only once through the transports by this condition */
if (tsp->asoc != assoc)
if (!list_is_first(&tsp->asoc->asocs, &ep->asocs))
return 0;
if (r->sdiag_family != AF_UNSPEC && sk->sk_family != r->sdiag_family)