From: David Yang Date: Wed, 21 Jan 2026 07:29:26 +0000 (+0800) Subject: net: openvswitch: fix data race in ovs_vport_get_upcall_stats X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cc4816bdb08639e5cd9acb295a02d6f0f09736b4;p=thirdparty%2Fkernel%2Flinux.git net: openvswitch: fix data race in ovs_vport_get_upcall_stats In ovs_vport_get_upcall_stats(), some statistics protected by u64_stats_sync, are read and accumulated in ignorance of possible u64_stats_fetch_retry() events. These statistics are already accumulated by u64_stats_inc(). Fix this by reading them into temporary variables first. Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets") Signed-off-by: David Yang Acked-by: Ilya Maximets Reviewed-by: Eric Dumazet Reviewed-by: Aaron Conole Link: https://patch.msgid.link/20260121072932.2360971-1-mmyangfl@gmail.com Signed-off-by: Paolo Abeni --- diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c index 6bbbc16ab778..f0ce8ce1dce0 100644 --- a/net/openvswitch/vport.c +++ b/net/openvswitch/vport.c @@ -310,22 +310,23 @@ void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats) */ int ovs_vport_get_upcall_stats(struct vport *vport, struct sk_buff *skb) { + u64 tx_success = 0, tx_fail = 0; struct nlattr *nla; int i; - __u64 tx_success = 0; - __u64 tx_fail = 0; - for_each_possible_cpu(i) { const struct vport_upcall_stats_percpu *stats; + u64 n_success, n_fail; unsigned int start; stats = per_cpu_ptr(vport->upcall_stats, i); do { start = u64_stats_fetch_begin(&stats->syncp); - tx_success += u64_stats_read(&stats->n_success); - tx_fail += u64_stats_read(&stats->n_fail); + n_success = u64_stats_read(&stats->n_success); + n_fail = u64_stats_read(&stats->n_fail); } while (u64_stats_fetch_retry(&stats->syncp, start)); + tx_success += n_success; + tx_fail += n_fail; } nla = nla_nest_start_noflag(skb, OVS_VPORT_ATTR_UPCALL_STATS);