From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dl1-f48.google.com (mail-dl1-f48.google.com [74.125.82.48]) (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 F0865322B72 for ; Sat, 28 Mar 2026 18:23:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.48 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774722222; cv=none; b=TSstcIy6Sk6wJsKx507Mqf8wD7fUe5X360BdIkL4IaNmmbMyZWDZ277eqQMtU9lq4Ry8dgR2pL/x1bhZbr0N7FoB2e++s9yi/IbJazZUlYOSmjnXnrPwXImungFn7Fh76PLcBMJeTcPo/5gNlvI+Q7GOFKuQaYtrMHQojsVySL4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774722222; c=relaxed/simple; bh=UXf9Js4OX6tTkSIzHkuR+90XKZwQtpBNs8i5n5HWXjg=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=kHVdwxSj8NBh40WnXJpoIx6gJq/zh3JdWuRiGfLg6yKC4Wz0zhDpH1cb0cTcY/18pPlIPW3SPJARi5nhFwkWDSJqURLY4OG1VUjIb31QIq7jeyyEVQa/s4etEWFaatG4BS81Mb7ZOUsPDVyWZOoCvDB1011q8zsPcAHHLZ8W5w4= 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=a1NxZKWC; arc=none smtp.client-ip=74.125.82.48 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="a1NxZKWC" Received: by mail-dl1-f48.google.com with SMTP id a92af1059eb24-12713e56abdso1221922c88.1 for ; Sat, 28 Mar 2026 11:23:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1774722220; x=1775327020; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=ck8SaND5LSVaKjpPu/DWpG6HZzjjicvnW6N+Jnt60/g=; b=a1NxZKWCV5D79JpqGOGZCPsIRR0zxGxtdDh4SQQDimo0fipVWh7c25ov9WW4x7xxqo mw6pk3+m4HYEoYvE10ilfaNIz4DbnFZwobFmhk9/bvO6vgi/7MaXc33wIQvNGwEp+fJ9 0QIrOsccBSxI6/VCiEvXWuTcTW6q/LMwC7JMmbY1a4h4xyQjZOEVYNqujSrlN6muzSTB lF9HZNhVZtMCkSiT4BUEGsuQUeHoq0PUXy1O99Ix6yVIYU0x4tW+9GRsuBUADjDzBXVS PS1sErRTVFO5XaHzmFP5jrgynMjGpxK8ZawmPCl6lSeCvD/H2YIsLkTKDttxBh2/flBm olKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774722220; x=1775327020; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=ck8SaND5LSVaKjpPu/DWpG6HZzjjicvnW6N+Jnt60/g=; b=qmWsSnJ7HTbIM9vP5pM+4SsPMm6n94zPKXwKo5SzkjRogDea7jrTM1q0MmQA0MhlNU uhZ0HNvT1/kNR7gJB4aWT89+c88rItUmRxHXngx0QoYa+6JhclGW/a/Xji2vmsPIyg/E Ysxcyby/hncXr/E9S+lJqiVowNMFd+yfMOXkJa9NAk7HdCp4n3hE3gdorczr1J3YUjF4 4QP0dveUyfHqvwtkHBy9xS8JEAHwks32QlSH3DVhpVJQLQkAYwM3Kx43lpeDuco2jCAb lZUrhdSAH/R48jAT5SXh0ZdHlX9B6fLR/Hz4Gz9KrgDTMlc/DKpPvrazGKoEZlJUFKS8 aaJg== X-Gm-Message-State: AOJu0YyvUAQ83N1E/srLneW9PtslMO87BrDR0SjuarSN8tV9Q2Tc4+ze +FHRzJCLp761QsNXrtAicOUmeKGLAc6rctbf4w8VACNqjFh3Ib07NLi93lwscRhPeDTs0QKtJf4 y/aeR X-Gm-Gg: ATEYQzxPm71omA4lXivV2MOg0rdbTb7f/SRByW92sQErKghwfBYtahvfke+vqXLuDZJ 38cHBhQqG22H0yMRqXg8ll0zXRG+JMjRLYG+npttopAPV3553amoovlBLQ7Q3qUZl78SQ+8Ik7T kw9O/yg01aMUAIlDIt5ZbGHNVoOsv9+b60kt2VXA7AkinLFliJ23Ng0F6vZASyjyNQnlzTNruWA pPWdyi7MOJbSexPF6roHr5ssBa1bt81VGmvqxh1DZMZeHegZON9cgvsaMVKZ8CFiCFkEIKUpByY CXv5xn6ectdFdlrnkkjERGtYSGT7TBJY5Y4zMa/YHowBNNuVoTuMjkUX09VqbrCQdKCNdIRPJWo iARSaQmrF6sRMksmTH/huuKYat8WTdogGU0K38j332lHrtVlHhLgDmIXY6Ihv3tBNny/cxfomBX OUPgiXIJSOIr8BGxyMbl+kH2vezg0rXz3/ X-Received: by 2002:a05:7022:218:b0:128:d2b2:143b with SMTP id a92af1059eb24-12ab2fc895cmr2839251c88.9.1774722219965; Sat, 28 Mar 2026 11:23:39 -0700 (PDT) Received: from phoenix.lan ([104.202.29.139]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-12aba581027sm3133008c88.4.2026.03.28.11.23.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 28 Mar 2026 11:23:39 -0700 (PDT) From: Stephen Hemminger To: netdev@vger.kernel.org Cc: Stephen Hemminger Subject: [PATCH net 0/5] net/sched: netem: bug fixes found during AI-assisted review Date: Sat, 28 Mar 2026 11:21:44 -0700 Message-ID: <20260328182336.392817-1-stephen@networkplumber.org> X-Mailer: git-send-email 2.53.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit These bugs were identified while using AI-assisted code review of sch_netem.c to analyze the packet duplication re-entrancy problem (CVE-2025-37890, CVE-2025-38001), which are addressed in a separate series. The review uncovered several additional issues: - probability gaps in the 4-state Markov loss model where boundary values produce no state transition - queue limit check not accounting for reordered packets - PRNG reseeded on every tc change, breaking reproducibility - the core dequeue re-entrancy issue with child qdiscs causing HFSC eltree corruption and DRR class stalls - missing NULL termination on the tfifo linear list tail Stephen Hemminger (5): net/sched: netem: fix probability gaps in 4-state loss model net/sched: netem: fix queue limit check to include reordered packets net/sched: netem: only reseed PRNG when seed is explicitly provided net/sched: netem: restructure dequeue to avoid re-entrancy with child qdisc net/sched: netem: null-terminate tfifo linear queue tail net/sched/sch_netem.c | 222 ++++++++++++++++++++++++++---------------- 1 file changed, 140 insertions(+), 82 deletions(-) -- 2.53.0