From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
commit 6a33d8b73dfac0a41f3877894b38082bd0c9a5bc upstream.
Netlink event path is missing a synchronization point with GC
transactions. Add GC sequence number update to netns release path and
netlink event path, any GC transaction losing race will be discarded.
Fixes: 5f68718b34a5 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/netfilter/nf_tables_api.c | 30 ++++++++++++++++++++++++++----
1 file changed, 26 insertions(+), 4 deletions(-)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6899,6 +6899,22 @@ void nft_trans_gc_queue_sync_done(struct
}
EXPORT_SYMBOL_GPL(nft_trans_gc_queue_sync_done);
+static unsigned int nft_gc_seq_begin(struct nftables_pernet *nft_net)
+{
+ unsigned int gc_seq;
+
+ /* Bump gc counter, it becomes odd, this is the busy mark. */
+ gc_seq = READ_ONCE(nft_net->gc_seq);
+ WRITE_ONCE(nft_net->gc_seq, ++gc_seq);
+
+ return gc_seq;
+}
+
+static void nft_gc_seq_end(struct nftables_pernet *nft_net, unsigned int gc_seq)
+{
+ WRITE_ONCE(nft_net->gc_seq, ++gc_seq);
+}
+
static int nf_tables_commit(struct net *net, struct sk_buff *skb)
{
struct nftables_pernet *nft_net = net_generic(net, nf_tables_net_id);
@@ -6953,9 +6969,7 @@ static int nf_tables_commit(struct net *
while (++nft_net->base_seq == 0)
;
- /* Bump gc counter, it becomes odd, this is the busy mark. */
- gc_seq = READ_ONCE(nft_net->gc_seq);
- WRITE_ONCE(nft_net->gc_seq, ++gc_seq);
+ gc_seq = nft_gc_seq_begin(nft_net);
/* step 3. Start new generation, rules_gen_X now in use. */
net->nft.gencursor = nft_gencursor_next(net);
@@ -7083,7 +7097,7 @@ static int nf_tables_commit(struct net *
nf_tables_commit_release(net);
nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN);
- WRITE_ONCE(nft_net->gc_seq, ++gc_seq);
+ nft_gc_seq_end(nft_net, gc_seq);
mutex_unlock(&nft_net->commit_mutex);
return 0;
@@ -7898,11 +7912,19 @@ static int __net_init nf_tables_init_net
static void __net_exit nf_tables_exit_net(struct net *net)
{
struct nftables_pernet *nft_net = net_generic(net, nf_tables_net_id);
+ unsigned int gc_seq;
mutex_lock(&nft_net->commit_mutex);
+
+ gc_seq = nft_gc_seq_begin(nft_net);
+
if (!list_empty(&nft_net->commit_list))
__nf_tables_abort(net);
+
__nft_release_tables(net);
+
+ nft_gc_seq_end(nft_net, gc_seq);
+
mutex_unlock(&nft_net->commit_mutex);
WARN_ON_ONCE(!list_empty(&nft_net->tables));
}
Patches currently in stable-queue which might be from kroah.com@xxxxxxxxxxxxxxx are
queue-4.19/netfilter-nf_tables-bogus-ebusy-when-deleting-flowtable-after-flush-for-4.19.patch
queue-4.19/netfilter-nft_set_rbtree-switch-to-node-list-walk-for-overlap-detection.patch
queue-4.19/netfilter-nf_tables-validate-nfproto_-family.patch
queue-4.19/netfilter-nf_tables-unregister-flowtable-hooks-on-netns-exit.patch
queue-4.19/netfilter-nf_tables-fix-gc-transaction-races-with-netns-and-netlink-event-exit-path.patch
queue-4.19/netfilter-nft_set_rbtree-use-read-spinlock-to-avoid-datapath-contention.patch
queue-4.19/netfilter-nft_dynset-report-eopnotsupp-on-missing-set-feature.patch
queue-4.19/netfilter-nf_tables-discard-table-flag-update-with-pending-basechain-deletion.patch
queue-4.19/netfilter-nft_set_rbtree-skip-sync-gc-for-new-elements-in-this-transaction.patch
queue-4.19/netfilter-nf_tables-mark-set-as-dead-when-unbinding-anonymous-set-with-timeout.patch
queue-4.19/netfilter-nf_tables-reject-new-basechain-after-table-flag-update.patch
queue-4.19/netfilter-nf_tables-gc-transaction-race-with-netns-dismantle.patch
queue-4.19/netfilter-nftables-update-table-flags-from-the-commit-phase.patch
queue-4.19/netfilter-nf_tables-allow-nfproto_inet-in-nft_-match-target-_validate.patch
queue-4.19/netfilter-nft_set_rbtree-skip-end-interval-element-from-gc.patch
queue-4.19/netfilter-nf_tables-drop-map-element-references-from-preparation-phase.patch
queue-4.19/netfilter-nf_tables-gc-transaction-race-with-abort-path.patch
queue-4.19/netfilter-nf_tables-fix-memleak-when-more-than-255-elements-expired.patch
queue-4.19/netfilter-nft_set_rbtree-add-missing-expired-checks.patch
queue-4.19/netfilter-nf_tables-double-hook-unregistration-in-netns-path.patch
queue-4.19/netfilter-nft_dynset-relax-superfluous-check-on-set-updates.patch
queue-4.19/netfilter-nf_tables-defer-gc-run-if-previous-batch-is-still-pending.patch
queue-4.19/netfilter-nft_set_hash-try-later-when-gc-hits-eagain-on-iteration.patch
queue-4.19/netfilter-nft_dynset-fix-timeouts-later-than-23-days.patch
queue-4.19/netfilter-nf_tables-mark-newset-as-dead-on-transaction-abort.patch
queue-4.19/netfilter-nf_tables-don-t-skip-expired-elements-during-walk.patch
queue-4.19/netfilter-nftables-rename-set-element-data-activation-deactivation-functions.patch
queue-4.19/netfilter-nf_tables-gc-transaction-api-to-avoid-race-with-control-plane.patch
queue-4.19/netfilter-nf_tables-set-dormant-flag-on-hook-register-failure.patch
queue-4.19/netfilter-nf_tables-remove-busy-mark-and-gc-batch-api.patch
queue-4.19/netfilter-nf_tables-skip-dead-set-elements-in-netlink-dump.patch
queue-4.19/netfilter-nf_tables-adapt-set-backend-to-use-gc-transaction-api.patch
queue-4.19/netfilter-nft_set_rbtree-fix-overlap-expiration-walk.patch
queue-4.19/netfilter-nf_tables-fix-table-flag-updates.patch
queue-4.19/netfilter-nf_tables-do-not-compare-internal-table-flags-on-updates.patch
queue-4.19/netfilter-nft_set_rbtree-allow-loose-matching-of-closing-element-in-interval.patch
queue-4.19/netfilter-nftables-exthdr-fix-4-byte-stack-oob-write.patch
queue-4.19/netfilter-nft_set_rbtree-fix-null-deref-on-element-insertion.patch
queue-4.19/netfilter-nf_tables-pass-context-to-nft_set_destroy.patch
queue-4.19/netfilter-nf_tables-disable-toggling-dormant-table-state-more-than-once.patch
