From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 9F8983AFCEA; Wed, 20 May 2026 08:19:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779265160; cv=none; b=I1oSk146ZiQn+DAt537e84HO8f41OBem9lo2jI2ishaHqBOkFkPQzQ55RYtJLGMI7ZEw957dgkeelViHh3ygRdaQzl2AeqbCYBL1y2a4cRgjUeM7yt03KrygMBa3p01T7JWr6HwsuCECvHCrNy7KHiXUQRSXXyf5d2xEBU7ja8Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779265160; c=relaxed/simple; bh=egsexhbhZMn6N2VNXPeFT9FZiiU9sNsftvujWkJEIxM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=mPj2tGoNFeM6xI3t5/q81a9yWIs+rXSU9M7gOwjbt34zFcdrLDNJQLfd1+FR0KJOTK/ilL2FG+dKd/SHHf7X91r5hSpEiPA2sPrmtZ+0B4qy2i3fj9iBRcwVB2MNa6zN3zJ8lo0oU8DENpe22mzJdmOjHam70ii9lCUAQQpivIA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QGRWwolu; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QGRWwolu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A23C1F00893; Wed, 20 May 2026 08:19:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779265158; bh=GVDlYomtipo4qtAHTcknpPeYaQN/qiVuV/EAqg0FNOE=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=QGRWwoluHB1wxqmq1NnHTwUGrOw0HmNcITLn8Pe3aTepQ46r2jdkcAYNLOmQLC6Ws fAO7nMcK4IAkEmw7q1Rz88yVzOt27cWANLTYW1boJbIknXERD1KFDTQKy4tYZOuC8K Xa83/+bLmy01KovNY7i3HHz3XSz0Y55T2cD1454db7Enrehvtwru2MztE1Skbw8C6K TzwzSQ9MpvS02tzUSDzYmwgI436vCppFZB1Rztx7znFzz5ZPc7GKf2Bv7bJ/FVIRKG DWbYxGBPnHJkKZKcVSZ0d3B7MBNCEqN4D1I+B9cReO5mepsJHAHs9ie8fqs14ga6GT +nHHtsTbiaf7Q== From: "Mike Rapoport (Microsoft)" Date: Wed, 20 May 2026 11:18:55 +0300 Subject: [PATCH 1/3] selinux: use k[mz]alloc() to allocate temporary buffers Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260520-security-v1-1-831bd8e21dd0@kernel.org> References: <20260520-security-v1-0-831bd8e21dd0@kernel.org> In-Reply-To: <20260520-security-v1-0-831bd8e21dd0@kernel.org> To: James Morris , John Johansen , Ondrej Mosnacek , Paul Moore , "Serge E. Hallyn" , Stephen Smalley Cc: Mike Rapoport , apparmor@lists.ubuntu.com, selinux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-security-module@vger.kernel.org X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=2557; i=rppt@kernel.org; h=from:subject:message-id; bh=egsexhbhZMn6N2VNXPeFT9FZiiU9sNsftvujWkJEIxM=; b=owEBbQGS/pANAwAKATkDhibLDv2RAcsmYgBqDW51z/2b9a1wBbACD7Lqy3AESWFSJG96Ft/Fc u9GHWORn7qJATMEAAEKAB0WIQR45VhVpZkvn3TRr+k5A4Ymyw79kQUCag1udQAKCRA5A4Ymyw79 kesfB/95neKLPMgBSsir1CVvO5hzi/mjOmpGVmukHgd+jj7BYpflrDOxXDEgBs6XHWLBXr6p9JI xvWliqXNwwYOaRYZrG10Gbl4vCSoFGOQPMOCctQQm9FEIATJM8lY9frjkw41Nd9vpyDWOUNoaB2 3KByTXQIPueuUKZKZxZf990V0FXHun2IroxnjikC7dbpoD+Ok7KlOfCucRjXTKN283DLquejXI/ MXWd19xgl5hyQaJR8l/0oPy+zZfbJBFZRt//57o+nv0whqgh4IDwfpdTwytJ50DBSSXdYZ7OH1j GtKAKh+ZMI9rY83yzUXjIC1ZjMGgzVRheIfJSJrbV+SP0mx7 X-Developer-Key: i=rppt@kernel.org; a=openpgp; fpr=B8E96E880C4A40C3C1255AA8C532392DE6DA7CE9 Several functions in selinuxfs.c allocate temporary buffers using __get_free_page() or get_zeroed_page(). These buffers are used either to store a string generated by snprintf() (in sel_make_bools()) or to copy data from user (sel_read_avc_hash_stats() and sel_read_sidtab_hash_stats()). Such usage does not require struct page access and it is better to allocate these buffers with kzalloc()/kmalloc() that provide better scalability and more debugging possibilities. Replace use of get_zeroed_page() with kzalloc() and usage of __get_free_page() with kmalloc(). Link: https://lore.kernel.org/all/635405e4-9423-4a25-a6e7-e03c8ea0bcbe@redhat.com Signed-off-by: Mike Rapoport (Microsoft) --- security/selinux/selinuxfs.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 25ca7d714014..e7b884eedf80 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -1244,7 +1244,7 @@ static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_ char **names, *page; u32 i, num; - page = (char *)get_zeroed_page(GFP_KERNEL); + page = kzalloc(PAGE_SIZE, GFP_KERNEL); if (!page) return -ENOMEM; @@ -1290,7 +1290,7 @@ static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_ ret = sel_attach_file(bool_dir, names[i], inode); } out: - free_page((unsigned long)page); + kfree(page); return ret; } @@ -1349,14 +1349,14 @@ static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf, char *page; ssize_t length; - page = (char *)__get_free_page(GFP_KERNEL); + page = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!page) return -ENOMEM; length = avc_get_hash_stats(page); if (length >= 0) length = simple_read_from_buffer(buf, count, ppos, page, length); - free_page((unsigned long)page); + kfree(page); return length; } @@ -1367,7 +1367,7 @@ static ssize_t sel_read_sidtab_hash_stats(struct file *filp, char __user *buf, char *page; ssize_t length; - page = (char *)__get_free_page(GFP_KERNEL); + page = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!page) return -ENOMEM; @@ -1375,7 +1375,7 @@ static ssize_t sel_read_sidtab_hash_stats(struct file *filp, char __user *buf, if (length >= 0) length = simple_read_from_buffer(buf, count, ppos, page, length); - free_page((unsigned long)page); + kfree(page); return length; } -- 2.53.0