netfilter: nf_tables: disable toggling dormant table state more than once

JIRA: https://issues.redhat.com/browse/RHEL-1720
JIRA: https://issues.redhat.com/browse/RHEL-1721
Upstream Status: commit c9bd265

commit c9bd265
Author: Florian Westphal <[email protected]>
Date:   Fri Sep 15 15:18:11 2023 +0200

    netfilter: nf_tables: disable toggling dormant table state more than once

    nft -f -<<EOF
    add table ip t
    add table ip t { flags dormant; }
    add chain ip t c { type filter hook input priority 0; }
    add table ip t
    EOF

    Triggers a splat from nf core on next table delete because we lose
    track of right hook register state:

    WARNING: CPU: 2 PID: 1597 at net/netfilter/core.c:501 __nf_unregister_net_hook
    RIP: 0010:__nf_unregister_net_hook+0x41b/0x570
     nf_unregister_net_hook+0xb4/0xf0
     __nf_tables_unregister_hook+0x160/0x1d0
    [..]

    The above should have table in *active* state, but in fact no
    hooks were registered.

    Reject on/off/on games rather than attempting to fix this.

    Fixes: 179d9ba ("netfilter: nf_tables: fix table flag updates")
    Reported-by: "Lee, Cherie-Anne" <[email protected]>
    Cc: Bing-Jhong Billy Jheng <[email protected]>
    Cc: [email protected]
    Signed-off-by: Florian Westphal <[email protected]>

Signed-off-by: Florian Westphal <[email protected]>

Author: fw-strlen

net/netfilter/nf_tables_api.c

@@ -1159,6 +1159,10 @@ static int nf_tables_updtable(struct nft_ctx *ctx)
 	     flags & NFT_TABLE_F_OWNER))
 		return -EOPNOTSUPP;
 
+	/* No dormant off/on/off/on games in single transaction */
+	if (ctx->table->flags & __NFT_TABLE_F_UPDATE)
+		return -EINVAL;
+
 	trans = nft_trans_alloc(ctx, NFT_MSG_NEWTABLE,
 				sizeof(struct nft_trans_table));
 	if (trans == NULL)