From patchwork Sat Jan 20 12:05:27 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Erick Archer X-Patchwork-Id: 13524373 Received: from mout.gmx.net (mout.gmx.net [212.227.15.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 88DB6320F; Sat, 20 Jan 2024 12:06:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=212.227.15.15 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705752363; cv=none; b=MM9RkNVASByNOxx5Xh9gktDWxPpVre7x5JkVVyn4hNZ2d+AF2HaAz/DWyj+6rVaChvxi8PwhjfNAw+GztEO7gACPUDfGA/HnGgsq4QVFWh84dJrRLDYWXeGs4sJeXXNxinCUSxPC+XILeIvAKU6kTFthNEPJ9WpD9darWh4TqJo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705752363; c=relaxed/simple; bh=6WljTQzsAyyeU2bPKrlfnVK55eNKnNBym7B97HV0Oq8=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=tTw6U5eMFM6Q4cIiU6dEnlDDqTHnxy1fFHGwyzbkWiKjVRpYKvjVTRhFZFLVzyuJjVK/C0hhajdYmkNnlQo7c7lSdu14yfAIxmvrrhNqOjYZvvQ8DeBVvrXAd3nkbyfrBalbHLLz+93hT7PrpqBsQ/5i5fG+hBPQSSzsV54Xp34= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.com; spf=pass smtp.mailfrom=gmx.com; dkim=pass (2048-bit key) header.d=gmx.com header.i=erick.archer@gmx.com header.b=BrOEHDwk; arc=none smtp.client-ip=212.227.15.15 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmx.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmx.com header.i=erick.archer@gmx.com header.b="BrOEHDwk" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.com; s=s31663417; t=1705752347; x=1706357147; i=erick.archer@gmx.com; bh=6WljTQzsAyyeU2bPKrlfnVK55eNKnNBym7B97HV0Oq8=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date; b=BrOEHDwkuzbLg79L4PnWJ5cxHqwsUPGnDQlzwnCN23SVhzi6ijC0Tv1jrg6O68I6 bgKDWf2hDN1oiap2qVwhQbk08J9RJwuiYICzpZq/tC5toKmrV1c2BH3O5R/AndJ6w 6lnMvuQTKXfM6ieXplXycc5ZQxDSY3j6ujnz8S7kfNEP2Zmmm+04z5/NZ967Z+oGl VBiwji4G0+8IAOO/41O3jtSCoav6fDkwyfgnVEC9YzagVt0Cgx5ip1WI0fAmkl0bU Ew9BnFALOWwVR6zbNCs2k3xAiXlVjuTtSqhEydplE8j9QbDFzXfokZf/KTg0JHYeO CO8E59t+xuXfoG+jPw== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from localhost.localdomain ([79.157.194.183]) by mail.gmx.net (mrgmx004 [212.227.17.184]) with ESMTPSA (Nemesis) id 1M42jK-1rRA6d0MNM-0007t9; Sat, 20 Jan 2024 13:05:47 +0100 From: Erick Archer To: Viresh Kumar , Nishanth Menon , Stephen Boyd , "Rafael J. Wysocki" , Len Brown , Pavel Machek , "Gustavo A. R. Silva" Cc: Erick Archer , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH] Documentation: power: Use kcalloc() instead of kzalloc() Date: Sat, 20 Jan 2024 13:05:27 +0100 Message-Id: <20240120120527.3866-1-erick.archer@gmx.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Provags-ID: V03:K1:MIB9rwFGn8LGmiHnZumtukOyb3RsmEdtPJtv639NvUDu4wkg9uM le8LXDqp2lj65dhD4DGvmd/RgkaUGRutEb5zp+iAzNeRObT2S888ysTeqpbHoA4FjZ42pLk 9YGTRAU8XT/RGai5CDlb93x6J5MGbpvFQt4PfhYsyWqBX84cBPsN1h1hcWmIbxJaY/vLSuE sGL8nyiOVW2uOmvnoWfnQ== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:PsIHd0DBSB0=;22SfptT7jfkPKbSIQF/aARbTyJB 7CsB1+3GKQZPBMDm6m6A1cLTA+wqnNwt3jQQ+MRxgI/hDEwgHzunaygKkU2IcM0b6RQimNthH KP4j7g7yokE/ezd45sO2wVY4/ruxS4HHDPOx0BnYWet8oESRM/Z5yLGEeJPzKjq8/hHIrDSGv Fl+2Xn5f5NrsWN8loLa5I9yvgXxWmnheBtPcsGmglHtS6KpcYxjAqktBxd/WG/Jkw9KJPl+xm f5HFcurAHxJGCc2q0xPWU51EOtf+s3IpS4yH4JghXX9X7pzh9xdXDoD8hNgIG2NFcDDUygkDl UFHtBcyKKEO/FIq6rby3SrTGyOofBc3XQSsGOJXrJBZpGD0/CyDb+BoVNDBVyoGkyDjFXc1x9 1i8dIc7wUqoM5gfSudJKYTHVh9zRXN2IlHwhfmoteIO7xvCJd8K5Gy4tTK1Mj4J2o3mQ3B/AO 06eTiozOauzv4Ji8eoT5w/5hgZhtNYQPbm0J/zTNa2GSHluJcvoiCaZZiXYhEPBut+rI6vKg8 KyhHnWCRWeymlBT7AWVACMYh21g7F+CJd5MKEgL9wMb8bzgpV6qNmk0bJGlox50UGXSg+kww2 4kNyLOs4k48NTPfklUjgwwSRa8fO2MOIuDmljihXo5Oe/f4WQS40f77+a8RfuCPIxTg8oPtOQ ktEQzdDFhlUoqoHuPe7hCzdQnzZB/+U6yprJKu/fwbH4W+J/0zlSM4w5503IR7yEJHyEeA+Oh Q8pLJSkXjjDzBPm8Uenw3WkViByynOwibtRixMNAOoWHgpYbYF1vymVYgBMm99v7hbO0AHg0m 6Gf14DocWNBTnZZo8fc4rtrLCmvXZPTdaggV/F1UAvrKC75hFvy8LL5HpsQa42hG5XUpRfUod Qow3M81VdaPFkn/gkXwrT+993mpPCJmTDpEowFBI5IwP8PsLywlgEY/xc8/FAykVeJlPfv4o/ dPoRx0KepLuBZYyfTtzcSIcy11g= As noted in the "Deprecated Interfaces, Language Features, Attributes, and Conventions" documentation [1], size calculations (especially multiplication) should not be performed in memory allocator (or similar) function arguments due to the risk of them overflowing. This could lead to values wrapping around and a smaller allocation being made than the caller was expecting. Using those allocations could lead to linear overflows of heap memory and other misbehaviors. So, in the example code use the purpose specific kcalloc() function instead of the argument size * count in the kzalloc() function. Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [1] Link: https://github.com/KSPP/linux/issues/162 Signed-off-by: Erick Archer --- Documentation/power/opp.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.25.1 diff --git a/Documentation/power/opp.rst b/Documentation/power/opp.rst index a7c03c470980..1b7f1d854f14 100644 --- a/Documentation/power/opp.rst +++ b/Documentation/power/opp.rst @@ -305,7 +305,7 @@ dev_pm_opp_get_opp_count { /* Do things */ num_available = dev_pm_opp_get_opp_count(dev); - speeds = kzalloc(sizeof(u32) * num_available, GFP_KERNEL); + speeds = kcalloc(num_available, sizeof(u32), GFP_KERNEL); /* populate the table in increasing order */ freq = 0; while (!IS_ERR(opp = dev_pm_opp_find_freq_ceil(dev, &freq))) {