From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71419C77B7E for ; Sun, 28 May 2023 19:22:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229985AbjE1TWt (ORCPT ); Sun, 28 May 2023 15:22:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40412 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229984AbjE1TWs (ORCPT ); Sun, 28 May 2023 15:22:48 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E618EC for ; Sun, 28 May 2023 12:22:45 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D503961B6C for ; Sun, 28 May 2023 19:22:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F1C66C433D2; Sun, 28 May 2023 19:22:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1685301764; bh=4LF0XKj7irR7X2JXIKKtAhKxZntiSv1je4UdTmZXwD0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cXy0IDLztMibAe0vZ07fAQVcb48t9g9cN+FFNyh0Oi+FaoPIT6EQkrEDt/fuo6+sp /G4yHH+xzDR81dxbtyQdmK6g8zqhJIrmhEtgIzIXaqnYWOs+J0R4NYX1bKx9h6XcR2 XLKd8YhKko64CIF1cSHz6noyBr6KG5fU9GSy//F4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Justin Tee , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 5.4 026/161] scsi: lpfc: Prevent lpfc_debugfs_lockstat_write() buffer overflow Date: Sun, 28 May 2023 20:09:10 +0100 Message-Id: <20230528190838.008468811@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230528190837.051205996@linuxfoundation.org> References: <20230528190837.051205996@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Justin Tee [ Upstream commit c6087b82a9146826564a55c5ca0164cac40348f5 ] A static code analysis tool flagged the possibility of buffer overflow when using copy_from_user() for a debugfs entry. Currently, it is possible that copy_from_user() copies more bytes than what would fit in the mybuf char array. Add a min() restriction check between sizeof(mybuf) - 1 and nbytes passed from the userspace buffer to protect against buffer overflow. Link: https://lore.kernel.org/r/20230301231626.9621-2-justintee8345@gmail.com Signed-off-by: Justin Tee Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/lpfc/lpfc_debugfs.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/lpfc/lpfc_debugfs.c b/drivers/scsi/lpfc/lpfc_debugfs.c index 69551132f304c..291fccf02d453 100644 --- a/drivers/scsi/lpfc/lpfc_debugfs.c +++ b/drivers/scsi/lpfc/lpfc_debugfs.c @@ -2046,6 +2046,7 @@ lpfc_debugfs_lockstat_write(struct file *file, const char __user *buf, char mybuf[64]; char *pbuf; int i; + size_t bsize; /* Protect copy from user */ if (!access_ok(buf, nbytes)) @@ -2053,7 +2054,9 @@ lpfc_debugfs_lockstat_write(struct file *file, const char __user *buf, memset(mybuf, 0, sizeof(mybuf)); - if (copy_from_user(mybuf, buf, nbytes)) + bsize = min(nbytes, (sizeof(mybuf) - 1)); + + if (copy_from_user(mybuf, buf, bsize)) return -EFAULT; pbuf = &mybuf[0]; @@ -2074,7 +2077,7 @@ lpfc_debugfs_lockstat_write(struct file *file, const char __user *buf, qp->lock_conflict.wq_access = 0; } } - return nbytes; + return bsize; } #endif -- 2.39.2