From patchwork Tue Apr 26 08:21:29 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 567903 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 74AA1C433EF for ; Tue, 26 Apr 2022 08:49:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231946AbiDZIwn (ORCPT ); Tue, 26 Apr 2022 04:52:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55576 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347343AbiDZIvU (ORCPT ); Tue, 26 Apr 2022 04:51:20 -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 63D8DD0A80; Tue, 26 Apr 2022 01:40:12 -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 B4F776104A; Tue, 26 Apr 2022 08:40:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4291C385B0; Tue, 26 Apr 2022 08:40:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650962411; bh=QWLitrRvFmVyVyJOX1rFDP8ZYjWDXNK6XBXYNABfqg0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XiXaC0KUNB1O3jxleJlZFZKueqJY3c2oleBs2Is6VvJypdYjeaP+zESH/P0TBg2Pd 3FwbepJyzbiLw3gabea7bT1PZjEKKJiT5o+ypJDYpFnKQEF82UE8pxvCGjWIL0ZCcP Btya+hW8kHPuMKkhD4g9mUtPugBvVg2B5kCyeGVY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christoph Hellwig , Tom Rix , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 5.15 088/124] scsi: sr: Do not leak information in ioctl Date: Tue, 26 Apr 2022 10:21:29 +0200 Message-Id: <20220426081749.801857443@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220426081747.286685339@linuxfoundation.org> References: <20220426081747.286685339@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tom Rix [ Upstream commit faad6cebded8e0fd902b672f220449b93db479eb ] sr_ioctl.c uses this pattern: result = sr_do_ioctl(cd, &cgc); to-user = buffer[]; kfree(buffer); return result; Use of a buffer without checking leaks information. Check result and jump over the use of buffer if there is an error. result = sr_do_ioctl(cd, &cgc); if (result) goto err; to-user = buffer[]; err: kfree(buffer); return result; Additionally, initialize the buffer to zero. This problem can be seen in the 2.4.0 kernel. Link: https://lore.kernel.org/r/20220411174756.2418435-1-trix@redhat.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Christoph Hellwig Signed-off-by: Tom Rix Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/sr_ioctl.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/sr_ioctl.c b/drivers/scsi/sr_ioctl.c index ddd00efc4882..fbdb5124d7f7 100644 --- a/drivers/scsi/sr_ioctl.c +++ b/drivers/scsi/sr_ioctl.c @@ -41,7 +41,7 @@ static int sr_read_tochdr(struct cdrom_device_info *cdi, int result; unsigned char *buffer; - buffer = kmalloc(32, GFP_KERNEL); + buffer = kzalloc(32, GFP_KERNEL); if (!buffer) return -ENOMEM; @@ -55,10 +55,13 @@ static int sr_read_tochdr(struct cdrom_device_info *cdi, cgc.data_direction = DMA_FROM_DEVICE; result = sr_do_ioctl(cd, &cgc); + if (result) + goto err; tochdr->cdth_trk0 = buffer[2]; tochdr->cdth_trk1 = buffer[3]; +err: kfree(buffer); return result; } @@ -71,7 +74,7 @@ static int sr_read_tocentry(struct cdrom_device_info *cdi, int result; unsigned char *buffer; - buffer = kmalloc(32, GFP_KERNEL); + buffer = kzalloc(32, GFP_KERNEL); if (!buffer) return -ENOMEM; @@ -86,6 +89,8 @@ static int sr_read_tocentry(struct cdrom_device_info *cdi, cgc.data_direction = DMA_FROM_DEVICE; result = sr_do_ioctl(cd, &cgc); + if (result) + goto err; tocentry->cdte_ctrl = buffer[5] & 0xf; tocentry->cdte_adr = buffer[5] >> 4; @@ -98,6 +103,7 @@ static int sr_read_tocentry(struct cdrom_device_info *cdi, tocentry->cdte_addr.lba = (((((buffer[8] << 8) + buffer[9]) << 8) + buffer[10]) << 8) + buffer[11]; +err: kfree(buffer); return result; } @@ -384,7 +390,7 @@ int sr_get_mcn(struct cdrom_device_info *cdi, struct cdrom_mcn *mcn) { Scsi_CD *cd = cdi->handle; struct packet_command cgc; - char *buffer = kmalloc(32, GFP_KERNEL); + char *buffer = kzalloc(32, GFP_KERNEL); int result; if (!buffer) @@ -400,10 +406,13 @@ int sr_get_mcn(struct cdrom_device_info *cdi, struct cdrom_mcn *mcn) cgc.data_direction = DMA_FROM_DEVICE; cgc.timeout = IOCTL_TIMEOUT; result = sr_do_ioctl(cd, &cgc); + if (result) + goto err; memcpy(mcn->medium_catalog_number, buffer + 9, 13); mcn->medium_catalog_number[13] = 0; +err: kfree(buffer); return result; }