From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f169.google.com (mail-yw1-f169.google.com [209.85.128.169]) (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 191EC3DB64B for ; Thu, 27 Aug 2026 23:55:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.169 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787874915; cv=none; b=lgsxWFXQYuYx7/8t0ZD8AMLIjFRyhCGlGGSCsBOwV5XN1h1Uo1wNvf0UuQSiBx5xg5mG3D1qG9FklrA94mVLm4W9SfBwY01lVN/r8MPTjGc82cB+PgCAfxcB8Q8IqF70R3ftiaOB0LYLqUBqyMyqXUlLnSs8/7jaN7x7lUC5tf4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787874915; c=relaxed/simple; bh=h27YVKK/TYuusXE6taFKqIAn5VyxSn/kotJtG8PpEoM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=GzoyD0s6LgvXIXaGMhDFvjQ0gGtoSD0EdVbrg23qPGVttunG4q9jCjFA0bJ/env1mQ9W6gINNUf6kJtzRGFVMaO9tsvnBe13Bbz6iZfssrNDKlQrDUdZHmDLF8Ns7a8joDwFtZpE3OVZhCYU7mEFlOMm5FuzNO1OFBkBj480E7E= 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=kLQV9XvF; arc=none smtp.client-ip=209.85.128.169 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="kLQV9XvF" Received: by mail-yw1-f169.google.com with SMTP id 00721157ae682-85a50f6a7f7so3086367b3.2 for ; Thu, 27 Aug 2026 16:55:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1787874913; x=1788479713; 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=oCfWHkIpmLvJEZNt0kO4ZWyCArHHxMdSOeCJ5Kkvn7k=; b=kLQV9XvFAFdSVgqCBBMav4u7yyVUl9B106WF7pEaIjoaVjR36RWCvJOyFkKOYLwSYC XeTjjTaHxmqjDWR9V3NPoLvqLmtt6Z43dU/wjEfOtshfAXQrZ0acatlEscg6uy2h714x d7uiB1SffbO0UaJvTFWYOFBPnyVgYBphj5pkPEBwhX/fFUGSzugmKjvacgX+ztmQvtuD 5kPA4sjnGAaHD9jPPMTaJ80IMryuuWysV95/8WfYDlQusgtTTyXCjA9yWJOkeI3A/v8h rPXPUvsw2q0lK1W8YWFvsCKJspoHf5e1LYwy3zt/R37idJBkGJfnZ+Id4DHjwD2a/gK+ yCIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787874913; x=1788479713; 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=oCfWHkIpmLvJEZNt0kO4ZWyCArHHxMdSOeCJ5Kkvn7k=; b=gZKCD0A9a0Q9RJYLcgn2WEGegmb1UGBnIHccFykTnzsx0wWxtbWZdb4iO4bn39tkMV Un2NkepioFg/FR8XjDvjgLvtSa2kLZQHzoe/R8I92sIf6ACBOa7kH5pgpXnnpTWs5Gq8 l4b15TEDTqhPyhKvbcWJOEJaZq/YB/djtFjTbzdtASc8Dd3gAxCKepAO9FsJ1IQ//d48 ulrsgSkZh8D47mTdhwi68AnyGvx6+LRrVcIJ6KpUKq6kMa6QjCXbhT3XIJR1NDLh8xrA EIjeM4feoRGVIpwG2cSwNQ8KgwSOQtyA+zC4xJkh060D8kx+MhjWFLMS9Dbkl/IsLW78 4cyg== X-Forwarded-Encrypted: i=1; AHgh+RonVxRhHQxPkvV3SohNYreUhKypYUDQPzK8AvtI9cT4gDAlkwDDG27X6+RmMX/rq3RLTMQ=@vger.kernel.org X-Gm-Message-State: AFuF++kpJWK9U17T/1LtHEa1EjIdIijkcPXNrrWY3q1/IydLBGdoAdx5 rbdvCIUlTUURJc7pGy57egTUqnXtzMzimP5pjB/FLP1YQVMySE7peoTA X-Gm-Gg: AR+sD10by3saFaxwMA/Qrioxi9YKaw5SBqYAZyOL9JyjQHSLbEq7CMaY+7+2YHsRir4 QT2PAKSAVhBWq4pS3DA5u3VOVTSv3lE+1YD1yIlVa3VDvvwouNs2Z20WGyORg6ZyqXvzZWVgxSq V2R0D/WRWidJkCRbZE4ruCMh8OVTHWZuTQoSvPU/DgWFDNrP98dCgLatHbmMmWRFq7fPbJ3HrTw cvuquA8TlZ1WwmpasfBi0FmaetgYm1iV9C6WxJIG94cgazRBYo6a+QL4cNdKY8M3Ovx8oGK5uuC j+xHE3bSuRiDsNkW757xodZ5cHyp/mXeIEac+CMovmqZSeeELxmF/a8C0TwB0w1kBZZ3P1/ZT0F J+9zFXosjYdQIB2I2hwEa1A0dTe54SGCZ3rL9XoD9bZPoIlb18HbWGC9G8U8Wt0KezYZqg/3/WO FMUa7Yua7s7HRlqB9osuVBLG3nmEgLBs/S7bBpkjC8hLZKPgEdoAV86LfI4PP66UwUi6o= X-Received: by 2002:a05:690e:428b:10b0:66c:d353:948a with SMTP id 956f58d0204a3-66e4c7645d8mr742101d50.39.1787874913018; Thu, 27 Aug 2026 16:55:13 -0700 (PDT) Received: from mac.lan ([136.55.173.105]) by smtp.gmail.com with ESMTPSA id 956f58d0204a3-66e4eb3dcdbsm55704d50.4.2026.08.27.16.55.12 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Thu, 27 Aug 2026 16:55:12 -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 v3 0/2] tcp: fix use-after-free in do_tcp_getsockopt() Date: Thu, 27 Aug 2026 19:55:09 -0400 Message-ID: X-Mailer: git-send-email 2.55.0 Precedence: bulk X-Mailing-List: bpf@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 the relevant icsk_ca_ops stores 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 v2 [1]: - Fix the TCP_CONGESTION build failure by loading icsk_ca_ops inline. - Drop the unrelated WRITE_ONCE() conversion in mptcp_ca_reset(). - Add READ_ONCE() to dctcp_get_info()'s icsk_ca_ops comparison. Changes in v2 [2]: - 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 [3]. [1] https://lore.kernel.org/all/20260826171344.4133-1-blbllhy@gmail.com/ [2] https://lore.kernel.org/all/20260821182449.79785-1-blbllhy@gmail.com/ [3] 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 | 4 ++-- net/ipv4/tcp_minisocks.c | 2 +- net/ipv4/tcp_output.c | 2 +- 5 files changed, 20 insertions(+), 10 deletions(-) base-commit: a3dee9bb902ee4357fa02e49b415d7724ee0140a -- 2.43.0