From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f45.google.com (mail-wr1-f45.google.com [209.85.221.45]) (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 7984538CFF6 for ; Wed, 29 Apr 2026 17:56:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.45 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777485378; cv=none; b=AtMHQIEJxFpb/rrrCEteBEHXvCafsYjoy9dVEBMTpz4finekBQYxIIxhUbsPHZGDpBP0UGwHBEfkjqiYXk5XqPnHB6ZHNggI4qKw0s2T9YR9+wSjTve1YXot9MP4QmJTBImxGj10XcYmzlqr71DLTM2hvpe1lV2qsv7USU5dQLs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777485378; c=relaxed/simple; bh=3OxTu4QNmh4FcfaWOckhLbkPnokTjOz1m2MKBETIPtI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=QHxxu8Ei9iFZLeNxC52SgcsU67KHla1kiZHFCw6ozaGc7UnQZZSnzBT3K3FpoKC/uW2MehtNsCcxxPbJRM7kaaYZGuyIfTzi2Q1udTY7csWIm8f5HMP/dk/oWNyu7wHa+8GIVHIXLBdtgU2huntJh57znh/yE6wxgd5cD7Ao+Vc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=TUoc0w6z; arc=none smtp.client-ip=209.85.221.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="TUoc0w6z" Received: by mail-wr1-f45.google.com with SMTP id ffacd0b85a97d-43d70b3e159so50313f8f.0 for ; Wed, 29 Apr 2026 10:56:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1777485375; x=1778090175; 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=r4NsrOL1q9Am89S8Z+OaW8+HqXPWLvbAymgwFLwuQBI=; b=TUoc0w6z/793eup5Y2+Wx9TN1zDZbPFz7ps9hUwk1FFnuKRsVcFPeL+2Gq8TFj89xb 7Skqkqp11WXWfyvxwc5pt52RHGC0dZLWcwch9vNGyG4875Z+B/wyt9li1PAtEMgabhX2 NAZURJLcsimuTEDpkjqf4u+CE231mnvJGzJBVSK6Lg9KcJck9Il4jsOXaFuZ9LInqSCe zJWqpPTf6ZIbfuCglXtkTCD2xaLMo3D+gOFzvPhMhx6XwGIJjDlNbJDFyu4yG1fGYpm1 /AUJxiXGWdnk2TS1xCTzSN9l5Lk0i9gSlOZbQHCgZzLJ6292xcU5CEItS1RBXWvh3iwc HJYQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777485375; x=1778090175; 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=r4NsrOL1q9Am89S8Z+OaW8+HqXPWLvbAymgwFLwuQBI=; b=WHx2y/BMD6PA5iU4jnd15hB1Vi7NA/IQYzKc5gxC2sDlXRSf5zrTciIo6zznDF43dL eIwiqH3zevH+xGFWU4s9KaKfk+Axzh8tkJqLpektWvTQ4BghIcateQynfATNzHBbv32k n9aN+sMqJGlCs+YfkMpjEZKR40OggtnbQAjUm795pyav/YxabPZf7t1/rmhh/MItiPjq fB5hNi6OGuh2Ad8lTQbyxC+Zpcdghohvw+nIsITcU4EpZ3yEYwsgMrpKTW0fgmhidjNy HDfv3iBHdw3Xb1BrYVUW0CKLLRl4Gk00EucMMeIkmdZIQRtQnY+gQ4oRB6cpbyxd8mj7 r/Zw== X-Forwarded-Encrypted: i=1; AFNElJ8Ux09Ydsjg3D2stvlzaN42xAoajgTu+PgSk2ubwQ6aBwkjYFN5zYMLMZsqDAND7SiqSNzM5jY=@vger.kernel.org X-Gm-Message-State: AOJu0Yx48umoxBi6Lg70YTtt7OunXN2tij78bMwlJkSRdq7Id1n0xAxi 9AcoIHCVvd94e36R5Dz3AeOmXne2pLaseaPQ+lAkyWiVB5vTIXpEqRLtFMop X-Gm-Gg: AeBDiesxzyprRI46Nq38DV7pBeRTqQtlinbYwVIwNy2k8/dY07GE+zHfZ+nrpTGsmja i5FIHVevXW7ufJSbQMFk2deRHIUom5G0RTRz0ZR5JAQ4BgIeom9SB7I8aYZguVkvRusAHP32XFd 2hSpBjiUAlPX/Nf133Ohb/xqNZ3AHFawpHC+fSVwCGeb7YUuBssgSKfhDLFGzsS4Lm9863NoK1s JtuCEkrDuqLGLjv57p+sm5sWWmKDO+7kBoea6y8uc+WcMRElwP+t5wgnn5AjyQrCmMWvPW2cSIy jC8z4F0/SEl58IEgo4BKa/Hl0eKG5H4F5KOj9yemQlbMLtW9r9hUfl14ZqORASgZYBuelNPbtOK TPotKvpC0qCnYOYxvhg8Dg67yj3a9vzat9ib6f9tlZeLcpM5vWEsvcCamgZDGrj6xvXW+APvXbn ZccvU= X-Received: by 2002:a05:6000:2305:b0:441:3144:efc5 with SMTP id ffacd0b85a97d-4464a1682b5mr16117702f8f.42.1777485374554; Wed, 29 Apr 2026 10:56:14 -0700 (PDT) Received: from debian.. ([2001:41d0:303:db6b::]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-447b3d48517sm6183750f8f.5.2026.04.29.10.56.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Apr 2026 10:56:13 -0700 (PDT) From: Tristan Madani To: Pablo Neira Ayuso Cc: Florian Westphal , Phil Sutter , netfilter-devel@vger.kernel.org, netdev@vger.kernel.org, stable@vger.kernel.org, linux-kernel@vger.kernel.org, Tristan Madani Subject: [PATCH 0/2] netfilter: fix NULL ops race in iptable lazy init Date: Wed, 29 Apr 2026 17:56:10 +0000 Message-ID: <20260429175613.1459342-1-tristmd@gmail.com> X-Mailer: git-send-email 2.47.3 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Tristan Madani ipt_register_table() and ip6t_register_table() call xt_register_table() which adds the new table to the per-netns list, making it visible to other code paths. Only afterwards do they allocate the per-net copy of hook ops via kmemdup_array(). This leaves a window where the table is findable via xt_find_table() but has ops=NULL. If cleanup_net runs during this window (racing namespace teardown against lazy table init), ipt_unregister_table_pre_exit() / ip6t_unregister_table_pre_exit() finds the table and passes the NULL ops pointer to nf_unregister_net_hooks(), causing a general protection fault. Fix both ip_tables.c and ip6_tables.c by moving the ops allocation before xt_register_table(), so the table is never in the list with a NULL ops pointer. Tristan Madani (2): netfilter: ip_tables: allocate hook ops before making table visible netfilter: ip6_tables: allocate hook ops before making table visible net/ipv4/netfilter/ip_tables.c | 31 ++++++++++++++++--------------- net/ipv6/netfilter/ip6_tables.c | 28 ++++++++++++++++------------ 2 files changed, 32 insertions(+), 27 deletions(-) -- 2.47.3