From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f42.google.com (mail-wm1-f42.google.com [209.85.128.42]) (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 8120F32C924 for ; Thu, 12 Feb 2026 22:12:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.42 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770934338; cv=none; b=P6KvNbL0D+5f0aLiCr6M1gHOJ0uNpYfQNwSnRzgiY7ooSPO/l+yAJypk4JyA8z/b3PEgq1X1G44ci9eXlKcSM/SaLjVo8qCGuAqX6ZtCpxTwpif2UZ+wY/aNj/3UylWo61WeJN0fHgL99LrtcxLY4rfBS/54P0BJ/gR8/1vU7+4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770934338; c=relaxed/simple; bh=GF6lofjVwO8F2sO2S/yR98Ft0GCJ/p8OaGLlVtdB1pY=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=Eq/UbYshrgOzKwgiRPM9MGCag6rWGj4uHLWwF12xdEkAXYOGepPfqSH+h3Y3VI0l3FoZhil73OGWvBJmV5SXKl7/IWu+x6u10H60kKX/IlZ/Aza7CjMC+gpO37OFQS4vpAkNgpXv8FyPJTYoOOTXe5HcZReRNdnHX0cGJSINNlA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=LodzLqmd; arc=none smtp.client-ip=209.85.128.42 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="LodzLqmd" Received: by mail-wm1-f42.google.com with SMTP id 5b1f17b1804b1-4806b0963a9so10435e9.0 for ; Thu, 12 Feb 2026 14:12:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1770934336; x=1771539136; darn=vger.kernel.org; h=cc:to:content-transfer-encoding:mime-version:message-id:date :subject:from:from:to:cc:subject:date:message-id:reply-to; bh=T5/73lXmUAGDF9goRsJB5ka+EvsW4ckCoSu6Noq3UtA=; b=LodzLqmdJisZk7R1Xf7eOpabvMr5jWhqhvZNbcKgNhD1PtRU3vHVAsIKFxmFFNCXAm iSTEu0xCOr7yzoDuyWr724ZwG0WxmOC8K3ETXR7p2TvIUOkCvf9MnAt4jTGb8Qd4NBEi zuy+WPOUpkgSZStJ7L0Ed6X84edfc/4z5bXKc83yVBquJ7skEhayafh/QCiHFiWN2jkK rE8Hj67+j4aEBouQZEBbnQfJhrp9OJ+FbLzNfU/xBKQwFUQKpAsHSD6GLodt4DZawCiT yUmDfZiBj1JrXzFiQCPz9zvgw3y4FhmJPnjOtnp3rtrrp1I72aBdSrr3vlwVzNgl+sTu h2yg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770934336; x=1771539136; h=cc:to:content-transfer-encoding:mime-version:message-id:date :subject:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=T5/73lXmUAGDF9goRsJB5ka+EvsW4ckCoSu6Noq3UtA=; b=k+le+kwANySMY60+Il26vnX0w20UBgjnVJX644V24g4e+0b9UqMsRwclQJgJwrPeGJ QjMhHg46W8dFrQatWxs0x/Vmu6/qV9AvHhXkyxpzcenM7TBKPXoEdV7E2KX8THAbdiYy mOQA//sMXilIcfzl4SRMvXYiSMQYaPQb8G6Su7Q8ik0FW2zZUvM6Vh6n7wA6wXIPSe4S sYdiksXC5BPuGTMWhzu9pFOrBaOOYXPa+HzivIou6DlLepA9Ebw3hSkmS5ZYvrtR4+2O IvdzVIV+6vyaQMQBA0rSvinGqgDg9zLQWirFGmLM1YptJumyklo7e5yiTe62HInugqHE 4iqA== X-Forwarded-Encrypted: i=1; AJvYcCWCiB4oRzAOaIKPPLhnX62lsE2XSt8xcPDzmJfUMh1hj38UixyBmvyTCcmbJ5SaUv8P4BFYds0tkjezev1c5w==@vger.kernel.org X-Gm-Message-State: AOJu0Yztce8w8v+u44doO6kEY9vq5q8pFWkuxXauXpUTexudpPoGDBHy 0M8otRT6kxyhwhuqK3tHcqDEKJyiIJIpQReYpkvH5cDJ/HeVsF5sFBeW8o3EE+pg3w== X-Gm-Gg: AZuq6aIb6En0snl+8HeMdPRHS6T30q67YLIq8kiIlF15tIeiyJCGfpQXGGa2RhfxnYR aFiImYK4XFsr/NTqoKy3B9Uqg3FAqu/avKN0XiLvLQvA+236AYniKx7B9d9Y00V/9q6+sS5tZP5 udz+6SVD7VL/9/Gn5k/UEMiHgNRR8C9Nq3YzNjpx7XkM9oJGISp/FN3N4Q65XSoVtiDFqt/JQch zW49huNJo9qlbgWvu0TpJbO1m3nE1fiR6joxStVRrHRFXAvLy0F0lgFybZZz1TDuCCvaxZYoJx+ ks5t01cSqj+awozG9Tl6eCxMSnQ9jND3X4kVvzFNa2go6vEuL6rXrDOQ+yxG1S970wqZ8ZlQ12O 32fvdsZiGIHTXmHIKlL/NNr2Hk2J3uLyUh4RdPG4eYXDOI3namGe3JngAA97q24xqTBXLXya64n OgcnsyOEuhFWPVF78+FsN7YlnmckQdjUnzkLSmseW8a6TcikBdSZjO7l1t+477Tw== X-Received: by 2002:a7b:cc97:0:b0:477:2f6f:44db with SMTP id 5b1f17b1804b1-48371ccb619mr38345e9.5.1770934335328; Thu, 12 Feb 2026 14:12:15 -0800 (PST) Received: from localhost ([2a00:79e0:288a:8:c531:3fec:ad3b:1a8d]) by smtp.gmail.com with UTF8SMTPSA id ffacd0b85a97d-43796a74704sm806687f8f.16.2026.02.12.14.12.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Feb 2026 14:12:13 -0800 (PST) From: Jann Horn Subject: [PATCH v2 0/2] rust: task: clean up safety issues wrt de_thread() Date: Thu, 12 Feb 2026 23:12:05 +0100 Message-Id: <20260212-rust-de_thread-v2-0-7d274c4fd02e@google.com> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIADVQjmkC/3XM0QrCIBTG8VcZ5zpDD25kV71HjHDzTIWaoSbF8 N2z3Xf5/+D7bZAoekpw7jaIVHzyYW2Bhw5mp1dLzJvWgBwHjgJZfKXMDN2yi6QN49oo0UtNZuL QTs9Ii3/v4HVs7XzKIX52v4jf+pcqggmm5GnpJ6VwQHmxIdg7HefwgLHW+gVBzJFdrQAAAA== X-Change-ID: 20260212-rust-de_thread-0ad9154aedb0 To: Miguel Ojeda , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich Cc: Wedson Almeida Filho , Martin Rodriguez Reboredo , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Jann Horn X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=ed25519-sha256; t=1770934330; l=883; i=jannh@google.com; s=20240730; h=from:subject:message-id; bh=GF6lofjVwO8F2sO2S/yR98Ft0GCJ/p8OaGLlVtdB1pY=; b=g98iJ8I5OHvAqt+o8QHwhnFyhQ42KmzZmqXtWLF5UkUld7x1jW7oOGb0cmGrU1uPt8p+KNEnt Z61Pw/oNGnxB4RFWEfom/iYH1WiUirZu5oFt5/YYT8scpWAoVNXYNg/ X-Developer-Key: i=jannh@google.com; a=ed25519; pk=AljNtGOzXeF6khBXDJVVvwSEkVDGnnZZYqfWhP1V+C8= Task::pid() and Task::group_leader() wrongly assume that task::pid and task::group_leader remain constant until the task refcount drops to zero, but those members can actually change due to concurrent de_thread(). Fix those assumptions. Signed-off-by: Jann Horn --- Changes in v2: - split into two patches (Boqun) - use relaxed atomic load instead of volatile load (Boqun) - Link to v1: https://lore.kernel.org/r/20260212-rust-de_thread-v1-1-948f5b992624@google.com --- Jann Horn (2): rust: task: limit group_leader() to current rust: task: use atomic read for pid() rust/kernel/task.rs | 38 ++++++++++++++++++++++---------------- 1 file changed, 22 insertions(+), 16 deletions(-) --- base-commit: 192c0159402e6bfbe13de6f8379546943297783d change-id: 20260212-rust-de_thread-0ad9154aedb0 -- Jann Horn