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Fri, 13 Mar 2026 14:17:16 -0700 (PDT) Received: from phoenix.lan ([104.202.29.139]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2aece81afccsm31204195ad.68.2026.03.13.14.17.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Mar 2026 14:17:16 -0700 (PDT) From: Stephen Hemminger To: netdev@vger.kernel.org Cc: Stephen Hemminger Subject: [PATCH 08/12] net/sched: netem: null-terminate tfifo linear queue tail Date: Fri, 13 Mar 2026 14:15:08 -0700 Message-ID: <20260313211646.12549-9-stephen@networkplumber.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260313211646.12549-1-stephen@networkplumber.org> References: <20260313211646.12549-1-stephen@networkplumber.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit When tfifo_enqueue() appends a packet to the linear queue tail, nskb->next is never set to NULL. The list terminates correctly only by accident if the skb arrived with next already NULL. Explicitly null-terminate the tail to prevent list corruption. Fixes: d66280b12bd7 ("net: netem: use a list in addition to rbtree") Signed-off-by: Stephen Hemminger --- net/sched/sch_netem.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index df9049816623..0f6817a472e6 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -408,6 +408,7 @@ static void tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch) q->t_tail->next = nskb; else q->t_head = nskb; + nskb->next = NULL; q->t_tail = nskb; } else { struct rb_node **p = &q->t_root.rb_node, *parent = NULL; -- 2.51.0