Commit a4e94117 authored Feb 09, 2023 by Pietro Borrello Committed by Greg Kroah-Hartman Feb 22, 2023

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



commit a1221703a0f75a9d81748c516457e0fc76951496 upstream.

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: 8f840e47 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent e1b54b56

net/sctp/diag.c

+1 −3

Original line number	Diff line number	Diff line
		@@ -349,11 +349,9 @@ 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)