netfilter: nft_set_hash: try later when GC hits EAGAIN on iteration

JIRA: https://issues.redhat.com/browse/RHEL-1720
JIRA: https://issues.redhat.com/browse/RHEL-1721
Upstream Status: commit b079155

commit b079155
Author: Pablo Neira Ayuso <pablo@netfilter.org>
Date:   Fri Sep 8 01:39:43 2023 +0200

    netfilter: nft_set_hash: try later when GC hits EAGAIN on iteration

    Skip GC run if iterator rewinds to the beginning with EAGAIN, otherwise GC
    might collect the same element more than once.

    Fixes: f6c383b ("netfilter: nf_tables: adapt set backend to use GC transaction API")
    Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Signed-off-by: Florian Westphal <fwestpha@redhat.com>

Author: fw-strlen

net/netfilter/nft_set_hash.c

@@ -338,12 +338,9 @@ static void nft_rhash_gc(struct work_struct *work)
 
 	while ((he = rhashtable_walk_next(&hti))) {
 		if (IS_ERR(he)) {
-			if (PTR_ERR(he) != -EAGAIN) {
-				nft_trans_gc_destroy(gc);
-				gc = NULL;
-				goto try_later;
-			}
-			continue;
+			nft_trans_gc_destroy(gc);
+			gc = NULL;
+			goto try_later;
 		}
 
 		/* Ruleset has been updated, try later. */