From nobody Wed Dec 17 10:44:28 2025 Received: from pv50p00im-ztdg10011301.me.com (pv50p00im-ztdg10011301.me.com [17.58.6.40]) (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 33B441640B for ; Fri, 12 Jul 2024 11:52:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=17.58.6.40 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720785172; cv=none; b=SKvi6VUFEGaR/ynF65M1cT7hF1cvwrZLGpAhMEVMPdJMiMVD0bSkEQttypm6dBYJ5Nuoa5BGEwvhxkxDMwhRsSMPPjai0zrqcSBHzuHsMll2jmEq/BJFFB0LAyQo0S/ytQf6IQYH7MPcBirPmjPYxuPyk1SOaKtyV1HwqHLQxNM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720785172; c=relaxed/simple; bh=iwpz2cJ6MASq82WXn4IytlPyAWih7fRpNA/6mCQB8RU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=NoBH+YFAQ3o5Hfu3K1UMgMRQ8A0zGO/kAHeg9+uiCaywcCGHN34SnYGPeAv8bWSlLgPMnsMfKDQopuRQaBmfZH8NkV21EGGFhYx93XUuvHq6gdzS1xf76b9hIqv7U1LIyjO1a1nVZVALfXxmVSEDq4sOqqnRDeAlqn8Tda8nJ3g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=icloud.com; spf=pass smtp.mailfrom=icloud.com; dkim=pass (2048-bit key) header.d=icloud.com header.i=@icloud.com header.b=hG7QApFm; arc=none smtp.client-ip=17.58.6.40 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=icloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=icloud.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=icloud.com header.i=@icloud.com header.b="hG7QApFm" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=icloud.com; s=1a1hai; t=1720785170; bh=hX0tJuSw+yu1u66K7bCO1ykDcSzKls85CioMXdu+/I4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To; b=hG7QApFmp76GSX+FskKdOSLlHsCVcv3QwzVMeeFJ6KB+Io5bk+xSDe+2pzGLaHw7I KZ59dZr0rNNxI9SpZIu6loldNGeAVMOCCtVpPm++yOokWXiHDW4Z2MeoLA1eZIGe0U /ETuIb6Emlr6ttLI9OXDvE3F/zYOM/SEUHjm28bgVk0/bZu2bNEZgI5iUrhOKEyrpP wr1zy6lM8m08hfeUPlyJ7GqWt5frljCqf+4myPrlkbSJJaldpHcPczGMvjZuzFVQsN eXfAv21ho6+jJ8Qxous72ArGu29RhCrlNpb8X4Px3M58+P6PJBkX3vAiwH+PKcstHB lr/LkhM/MnzWw== Received: from [192.168.1.26] (pv50p00im-dlb-asmtp-mailmevip.me.com [17.56.9.10]) by pv50p00im-ztdg10011301.me.com (Postfix) with ESMTPSA id 74372180429; Fri, 12 Jul 2024 11:52:47 +0000 (UTC) From: Zijun Hu Date: Fri, 12 Jul 2024 19:52:31 +0800 Subject: [PATCH v3] driver core: Fix size calculation of symlink name for devlink_(add|remove)_symlinks() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20240712-devlink_fix-v3-1-fa1c5172ffc7@quicinc.com> X-B4-Tracking: v=1; b=H4sIAP4YkWYC/22MSw7CIBQAr2JYi4EH/bnyHsaYCg/7olIFJZqmd 5d2ZROXM8nMwCIGwsi2q4EFTBSp9xnUesVM1/ozcrKZGQjQohIVt5iu5C9HR28uXKtLi9ZhU7B c3ANmPd/2h8wdxWcfPvM8ycn+/yTJJS9BteaklTS23j1eZMibjelvbDol+K2bZQ25BoBCOylVj XJZj+P4BfDmCermAAAA To: Greg Kroah-Hartman , "Rafael J. Wysocki" Cc: Saravana Kannan , linux-kernel@vger.kernel.org, Zijun Hu , Zijun Hu X-Mailer: b4 0.14.0 X-Proofpoint-GUID: N513KqiiN7cRdmIei7ybAriJcjGLxmAN X-Proofpoint-ORIG-GUID: N513KqiiN7cRdmIei7ybAriJcjGLxmAN X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.28.16 definitions=2024-07-12_07,2024-07-11_01,2024-05-17_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 clxscore=1015 phishscore=0 spamscore=0 mlxscore=0 mlxlogscore=868 suspectscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2308100000 definitions=main-2407120073 X-Apple-Remote-Links: v=1;h=KCk=;charset=UTF-8 From: Zijun Hu devlink_(add|remove)_symlinks() kzalloc() memory to save symlink name for both supplier and consumer, but do not explicitly take into account consumer's prefix "consumer:", so cause disadvantages listed below: 1) it seems wrong for the algorithm to calculate memory size 2) readers maybe need to count characters one by one of both prefix strings to confirm calculated memory size 3) it is relatively easy to introduce new bug if either prefix string is modified in future solved by taking into account consumer's prefix as well. Signed-off-by: Zijun Hu --- Changes in v3: - Correct commit message - Link to v2: https://lore.kernel.org/r/20240709-devlink_fix-v2-1-22254f113= 8e1@quicinc.com Changes in v2: - Correct commit message and add inline comments - Remove fix tag - Link to v1: https://lore.kernel.org/r/20240707-devlink_fix-v1-1-623acb431= cd8@quicinc.com --- drivers/base/core.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index 2b4c0624b704..51209db7ff84 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -572,7 +572,11 @@ static int devlink_add_symlinks(struct device *dev) len =3D max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)), strlen(dev_bus_name(con)) + strlen(dev_name(con))); len +=3D strlen(":"); - len +=3D strlen("supplier:") + 1; + /* + * we kzalloc() memory for symlink name of both supplier and + * consumer, so explicitly take into account both prefix. + */ + len +=3D max(strlen("supplier:"), strlen("consumer:")) + 1; buf =3D kzalloc(len, GFP_KERNEL); if (!buf) return -ENOMEM; @@ -623,7 +627,7 @@ static void devlink_remove_symlinks(struct device *dev) len =3D max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)), strlen(dev_bus_name(con)) + strlen(dev_name(con))); len +=3D strlen(":"); - len +=3D strlen("supplier:") + 1; + len +=3D max(strlen("supplier:"), strlen("consumer:")) + 1; buf =3D kzalloc(len, GFP_KERNEL); if (!buf) { WARN(1, "Unable to properly free device link symlinks!\n"); --- base-commit: c6653f49e4fd3b0d52c12a1fc814d6c5b234ea15 change-id: 20240707-devlink_fix-0fa46dedfe95 Best regards, --=20 Zijun Hu