From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f178.google.com (mail-yw1-f178.google.com [209.85.128.178]) (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 CEB524582D3 for ; Wed, 26 Aug 2026 17:14:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787764474; cv=none; b=q1xI97XkCe2CIwfmi3kmCoDwKKjge70NtJyo/h+Nj+7d/pCTo9QbYErv2MaQQvX+CXWM+uF8OvmC/b1duV+/GlxCbGd932MAmCbjl4qmQyS02wHyHLsk8w20YYrgx/Mvx6VJj9uG+CBTZIfpIJ1zw3ausIjNdF5PcJHQso8Y95s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787764474; c=relaxed/simple; bh=FYU7KMAFHEMK0a2QdB7zYECmQAGqWOP3hrjJRZA4Zgw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=vCoVyHXmuaV/eXiW2g3D99V43vcqgk+iHPoxWPjgMblslZIUu/Zwud7ki7aVv9UGtOnXItRGVka15D3+tgoUhc3mSq1+4Ng8s0faTbZW856+OSXwT+n4Ca4Jl0Yep01fQBRyBDNKbL33jzG7EA4YUKz11gmkATrsZl8H8LGKJP0= 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=JuR4/rWj; arc=none smtp.client-ip=209.85.128.178 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="JuR4/rWj" Received: by mail-yw1-f178.google.com with SMTP id 00721157ae682-854f9c32c76so2637607b3.0 for ; Wed, 26 Aug 2026 10:14:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1787764449; x=1788369249; 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:content-type; bh=3I8jJPf0z07/GaYv+UyScI71SC+rAjjfZUq3HdGlVP8=; b=JuR4/rWjJUesPnZfDT/1zN3cjhdoD0V0U7YXK1F0UaT3bdRqLn+DgngjRvhz8M2d0d 3Ij9iqlGcXI7NkC2ssdAQU1nymvvubqUmFxe9IlOG1kBQTLb40w1WfU44B/2q7QuIcgQ fXg/XA33t0uTwdfI2BtwEdylwBXe6Wh8Y9dVHdPvjMDstipah0KWO+AVarwceptPpaMh YYfu6UJYZWvlNpGltpZxU8nXjZIB68KXVoDOcaYOdpWEfNl6iadiiKICdDZYJYwLoXjC 7LoEuKVHAidJOmGHxx4YFaivCS66009mce7/cUpILPiyfZOu78ZOleF2vHGJQlq901bo cCAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787764449; x=1788369249; 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:content-type; bh=3I8jJPf0z07/GaYv+UyScI71SC+rAjjfZUq3HdGlVP8=; b=imCt1EHelqlPBHNrcBroVVmndqEMBeLU6jiGqmPKz6X+d7ovkmKnPO6Ab58A6PueMP J5rK5sDgWe4WhSvLzqdptN1N8O0uLm9pOA8SzKos3Yu3DIjDowIBze9KVnw9B9fBQPqy 1aVgPyOq1uA7SfY4pr8h9ziViy7EaNasFrHAbsMYwXNKqMklU7QVDGeNJ7ZIHYVgTQja l8bZjX+cdPUAk0Lf6oE/dyveouLMHWdbctTztXQ5AM984fs2QXsX4KnAPlBwPOCs0aXx J4XhuDzTwDgeOwr6qagkv9Ub9hpfHPPbNU8Cf/5i00AfpMv8coPULOV6ktcGnLzOVxiO Cxmw== X-Forwarded-Encrypted: i=1; AHgh+RrbewhEOBO5RCD6dfsMCZeSNddvOgZglPtxPlPvXsLUOtJR+GrZ987u6w2ksMvTqhTZegIWCYu0VFs9CKY=@vger.kernel.org X-Gm-Message-State: AFuF++mKY6EjZ/xi/FFmNzudGwUEoGVtEbRNN4xXwkC+UNag5evQCR6G QUW5Ou2hy1GAhXgPJntv9JPYHCyQajejXaUHS7vBSPtV+HPBhipYPg6L X-Gm-Gg: AR+sD13zOMZX2r4tRJUVZvYJ0Nm4TRQqWAGxo9TZ7OSy2gQ45Vt1uRYEDbbky+O9KD2 uV7ivF+Ndc37mvaL32WGTXyCm9hdV6MZJWuec4sTFVPgZ5n5c/2lI0ghzKEg7xNFFE4bKspWF81 xsM6Lkh0sSODHf2eIOY9QJurN9FuAXDcBrOQhVlrVNIfO92cFZ0aYuZR/hrbiEfL0ZRj5vFdypY /cVrP3bMdyhZmChBIAKgoWEq1vSVQdU4d22uJgK4+dZMpF6pVa8fUsOVatBKmaGxCUAiBA4ZWtt 5VEvRQ7UG4ov8RyGcPY0v8hWM09zJ/jB2wMWDYYwaA5Zsds9u7zjcL+YZZnfyl4tzm2W2w4cXdj 9euFduhg7rFILETjEUuk07YxEnO0bK4fKnhk6Xff5IOQ8o9TFpBFLr6xywqap+iD/6/TauKLD9f kFXX12hIyH4pRTDni22QJ3NkhtEEiLKwD54bH4fhf6WkdOaiopC2nH0CyOHE58/AvrLhk= X-Received: by 2002:a05:690c:3709:b0:826:f78b:8462 with SMTP id 00721157ae682-85a9ee40bd0mr3306087b3.7.1787764449016; Wed, 26 Aug 2026 10:14:09 -0700 (PDT) Received: from mac.lan ([136.55.173.105]) by smtp.gmail.com with ESMTPSA id 00721157ae682-8570d620433sm19313287b3.42.2026.08.26.10.14.08 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Wed, 26 Aug 2026 10:14:08 -0700 (PDT) From: "Cen Zhang (Microsoft)" To: edumazet@google.com, ncardwell@google.com, davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com Cc: kuniyu@google.com, horms@kernel.org, matttbe@kernel.org, martineau@kernel.org, geliang@kernel.org, yhs@fb.com, kafai@fb.com, andriin@fb.com, ast@kernel.org, netdev@vger.kernel.org, mptcp@lists.linux.dev, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, AutonomousCodeSecurity@microsoft.com, xmei5@asu.edu, tgopinath@linux.microsoft.com, kys@microsoft.com, blbllhy@gmail.com Subject: [PATCH net v2 0/2] tcp: fix use-after-free in do_tcp_getsockopt() Date: Wed, 26 Aug 2026 13:13:42 -0400 Message-ID: <20260826171344.4133-1-blbllhy@gmail.com> X-Mailer: git-send-email 2.55.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Cen Zhang (Microsoft Security FORGE Labs)" do_tcp_getsockopt() has two lockless reads of icsk_ca_ops. Since BPF struct_ops congestion control made icsk_ca_ops point to dynamically allocated memory, a concurrent setsockopt(TCP_CONGESTION) can replace the pointer and free the old object while either reader is using it. Patch 1 fixes the TCP_CONGESTION path by copying ca_ops->name to a stack buffer while holding rcu_read_lock(). It also uses READ_ONCE() for the lockless load and annotates every explicit icsk_ca_ops store with WRITE_ONCE(). Patch 2 fixes the TCP_CC_INFO path by keeping the READ_ONCE() load, ca_ops->get_info lookup, and call inside an RCU read-side critical section. Changes since v1 [1]: - Add READ_ONCE() to both lockless icsk_ca_ops loads. - Add WRITE_ONCE() to all six explicit icsk_ca_ops stores. - Include the data-race annotations in the UAF series as requested by Eric Dumazet [2]. [1] https://lore.kernel.org/all/20260821182449.79785-1-blbllhy@gmail.com/ [2] https://lore.kernel.org/all/CANn89iKr1ypEFeL+7te3xWoNaK5AFyYQmr+pDh2zSZAxfgNKjw@mail.gmail.com/ Cen Zhang (Microsoft Security FORGE Labs) (2): tcp: fix use-after-free in do_tcp_getsockopt(TCP_CONGESTION) tcp: fix use-after-free in do_tcp_getsockopt(TCP_CC_INFO) net/ipv4/tcp.c | 18 ++++++++++++++---- net/ipv4/tcp_cong.c | 4 ++-- net/ipv4/tcp_dctcp.c | 2 +- net/ipv4/tcp_minisocks.c | 2 +- net/ipv4/tcp_output.c | 2 +- net/mptcp/protocol.c | 2 +- 6 files changed, 20 insertions(+), 10 deletions(-) base-commit: f967455fb2a5a2079b9eb5823e9ccf359174bf9f -- 2.55.0