From: Eric Dumazet Date: Tue, 21 Apr 2026 14:25:09 +0000 (+0000) Subject: net/sched: sch_fq_codel: remove data-races from fq_codel_dump_stats() X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=bbfaa73ea6871db03dc05d7f05f00557a8981f25;p=thirdparty%2Fkernel%2Fstable.git net/sched: sch_fq_codel: remove data-races from fq_codel_dump_stats() fq_codel_dump_stats() acquires the qdisc spinlock a bit too late. Move this acquisition before we fill st.qdisc_stats with live data. Fixes: edb09eb17ed8 ("net: sched: do not acquire qdisc spinlock in qdisc/class stats dump") Signed-off-by: Eric Dumazet Reviewed-by: Jamal Hadi Salim Link: https://patch.msgid.link/20260421142509.3967231-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c index 2a3d758f67ab..0664b2f2d6f2 100644 --- a/net/sched/sch_fq_codel.c +++ b/net/sched/sch_fq_codel.c @@ -585,6 +585,8 @@ static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d) }; struct list_head *pos; + sch_tree_lock(sch); + st.qdisc_stats.maxpacket = q->cstats.maxpacket; st.qdisc_stats.drop_overlimit = q->drop_overlimit; st.qdisc_stats.ecn_mark = q->cstats.ecn_mark; @@ -593,7 +595,6 @@ static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d) st.qdisc_stats.memory_usage = q->memory_usage; st.qdisc_stats.drop_overmemory = q->drop_overmemory; - sch_tree_lock(sch); list_for_each(pos, &q->new_flows) st.qdisc_stats.new_flows_len++;