From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dl1-f47.google.com (mail-dl1-f47.google.com [74.125.82.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7CBF332F759 for ; Wed, 1 Apr 2026 14:53:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.47 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775055223; cv=none; b=QXf1bBjr4xuywGpickXv2pXtOQuKGJ4Lbfmr8nf2ltxYvXtwqlYjYtXFLZ+G9LFqN66p1I9L1T7/RlElG9OHGGjzlh8jGCNawf7LTIt0RPCbk6CaR1E469kaBgbR3GTh8QEScL7BaFqLR90zjAmK8y5df1ZQxnBFcAaZBsCj1tA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775055223; c=relaxed/simple; bh=/maizwT8ZGLjouDwcq4bTwlangICy3f4G/zLNjuMzbA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=X9X91o4jWl5ct5NWTIHI8k9okn++Z1f+/81p0VzOcXNvWW4P9XXOO8MMAt/X9AXZc7hmvh9HYAv2CgmZnB1gKTiNsZ7DGFEZ3IGzIWQyxVlY5NGol6SKbyFc+L9Glpb96WGu+Khec3ar0fVEjF1PnZlOKBr3JFPoNIgEx5wzyfY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=networkplumber.org; spf=pass smtp.mailfrom=networkplumber.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20230601.gappssmtp.com header.i=@networkplumber-org.20230601.gappssmtp.com header.b=yeqm1NmD; arc=none smtp.client-ip=74.125.82.47 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=networkplumber.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=networkplumber.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20230601.gappssmtp.com header.i=@networkplumber-org.20230601.gappssmtp.com header.b="yeqm1NmD" Received: by mail-dl1-f47.google.com with SMTP id a92af1059eb24-127380532eeso2422712c88.1 for ; Wed, 01 Apr 2026 07:53:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1775055222; x=1775660022; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=iB0cCE3WCvRC67Xf0AcW1ajnHgViG1QsyhPCjiMGj9k=; b=yeqm1NmDZa8s7bPxYQoO5mj7wQXWqjoeq4ICYcYgjXEdSafA2kIAudKSdse1uBUHs1 zkHDAh+5272v6gxIvUlt08TZJz/Avj3yAQwcbpC5cQHL3jL99LwdIfmnTQYpA0JJkYcD fVDQ6k0QFrze1Nuue/r273BXCP2WL5C6EXRrzeabpp6lyNCpalr/PCxOMOXyfemNVwCk F+wgziwgLJhYx8qg5VcFjqv3/UzTa8sp3/PZZycz3BPNj/fy17QOy8953d+dSM5bUrqz lHaAdtvyTdOwiPxiobOThHptnq8OBSbT+IyzYPUvo9FfdtS/j6MRFVKDSi44udvT6iXp 0zCQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775055222; x=1775660022; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=iB0cCE3WCvRC67Xf0AcW1ajnHgViG1QsyhPCjiMGj9k=; b=pr0PWX0PRZxdxUUAYppvKDWf7C39C+l0SoHEjXWpLi46ulp4SqDNIcJNtx6K9MSV79 Nw3BmPstfNZ8k7PbGzVC88N0DlKosIt0OcoG7IhcRql2lf909tudqLRcySFILCimOYMx /xQC5ViM57XC8Qu3k2UUCKmHI5gQfe+KT/JJS/HQJpkDagiUyyWT0hygPUzGoQhYKFyH aWXQxN2PNP2hR/xUomr/zYAUKbUhboNGZBeUiAE5hlL31ot54znLQwgWlNLoEK1ll7C3 UHIP+AAYxNX5MnSK6UAmADPqt2q30fW1eh7910jo9lQSpPhjvfRM1wkTvFIK+ay0Uwh7 1GVA== X-Forwarded-Encrypted: i=1; AJvYcCWuuJUbym4BC3igyNQ7X56cNyZ6NGU6hJ7AjaJo5RSObbzrbXOmWOIi0JYNxd8mopsViPwLqMlYksEmKbk=@vger.kernel.org X-Gm-Message-State: AOJu0YycO04qeb1+OQFUbNLMr1UXWaKq5zHFGHj14TTQSNc9g0nl+7Wf IeqD6l+VXYhXvmgeBTRaIkb+EZtKteRGbV8PhMZfBk5r3PDL8cZHlqxS4NsrXf9emKg= X-Gm-Gg: ATEYQzxSlBp62n1aFDF7T/hb78TDtWsfG9J4SqP7bRGGr6AU9yaIBkaviB/YLkWCTJe d5aVZ+vumvUdX9hHat7jZ0XCBCk5gpieBXdamAPkFKAPByKBMLlxSH0OZAblAsAGKP+ld5P5R2B xB91IfKOwfbxNWGClwUW27RMQez20xQmlirhXWtMH99kIYmjXArSvDgBkJRODsRvsea7c0KB4cC dXA1adoGeFLj+1LuFUVDuVNYxVeTdy8Qi16kbxrMUrgOWWM0K+byiE9jC0WDXEQNUrhBHH+Jmj1 foef/opg49H4bxEm2UHkMExZHSLM+Mutl3o5C1x3VfaQenMYnNLhSJpENXNrMJyE+YaNVWwQnKJ An2t6E5ZxxfJaDD/l1jbun/UqK0k5rvXkkQkGQPBqDv8BE8D4B/lEEoCLkxi2+VBah68brKy+xy Vod0yZOzGVC13uvT2N/++zLNqyrSftspVM X-Received: by 2002:a05:7300:6d1f:b0:2c1:55fd:50bb with SMTP id 5a478bee46e88-2c9327a243cmr2436416eec.20.1775055221725; Wed, 01 Apr 2026 07:53:41 -0700 (PDT) Received: from phoenix.lan ([104.202.41.210]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-2c3c3bda13csm12804830eec.6.2026.04.01.07.53.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Apr 2026 07:53:41 -0700 (PDT) From: Stephen Hemminger To: netdev@vger.kernel.org Cc: Stephen Hemminger , Jamal Hadi Salim , Jiri Pirko , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Peter Oskolkov , linux-kernel@vger.kernel.org (open list) Subject: [PATCH net v2 5/7] net/sched: netem: null-terminate tfifo linear queue tail Date: Wed, 1 Apr 2026 07:51:57 -0700 Message-ID: <20260401145332.78285-6-stephen@networkplumber.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260401145332.78285-1-stephen@networkplumber.org> References: <20260401145332.78285-1-stephen@networkplumber.org> Precedence: bulk X-Mailing-List: linux-kernel@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 ce12b64603b2..4b27fab72fef 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -398,6 +398,7 @@ 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; -- 2.53.0