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 6AA2DC433FE for ; Thu, 13 Oct 2022 18:15:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231743AbiJMSPp (ORCPT ); Thu, 13 Oct 2022 14:15:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38906 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231829AbiJMSMu (ORCPT ); Thu, 13 Oct 2022 14:12:50 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 010122BF5; Thu, 13 Oct 2022 11:09:44 -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 ams.source.kernel.org (Postfix) with ESMTPS id 7238FB8203F; Thu, 13 Oct 2022 17:56:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B18C1C433C1; Thu, 13 Oct 2022 17:56:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1665683778; bh=aehZ4fotnOMudzkfAbcWEupz02Xaa8+DcsAlTvfhbo8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V4oqem6eISdR5i1hnzDgcBJtb4mHDYPGHPvHIw6kQ1ZtXew2EJpdiQop8nYtSmCvA igxNTg0YhY/+WgPKVnK9kLkGZ0P8E7bDSiX6H54pgaHFBWj5BqsKgBSATQYoLSHeaZ RbbH8h999sScb1Ep0NZtBkidfnccqUGhgG/6pSrk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zheyu Ma , Saurav Kashyap , Wende Tan , Letu Ren , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 5.10 20/54] scsi: qedf: Fix a UAF bug in __qedf_probe() Date: Thu, 13 Oct 2022 19:52:14 +0200 Message-Id: <20221013175147.852564266@linuxfoundation.org> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221013175147.337501757@linuxfoundation.org> References: <20221013175147.337501757@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: linux-kernel@vger.kernel.org From: Letu Ren [ Upstream commit fbfe96869b782364caebae0445763969ddb6ea67 ] In __qedf_probe(), if qedf->cdev is NULL which means qed_ops->common->probe() failed, then the program will goto label err1, and scsi_host_put() will free lport->host pointer. Because the memory qedf points to is allocated by libfc_host_alloc(), it will be freed by scsi_host_put(). However, the if statement below label err0 only checks whether qedf is NULL but doesn't check whether the memory has been freed. So a UAF bug can occur. There are two ways to reach the statements below err0. The first one is described as before, "qedf" should be set to NULL. The second one is goto "err0" directly. In the latter scenario qedf hasn't been changed and it has the initial value NULL. As a result the if statement is not reachable in any situation. The KASAN logs are as follows: [ 2.312969] BUG: KASAN: use-after-free in __qedf_probe+0x5dcf/0x6bc0 [ 2.312969] [ 2.312969] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 [ 2.312969] Call Trace: [ 2.312969] dump_stack_lvl+0x59/0x7b [ 2.312969] print_address_description+0x7c/0x3b0 [ 2.312969] ? __qedf_probe+0x5dcf/0x6bc0 [ 2.312969] __kasan_report+0x160/0x1c0 [ 2.312969] ? __qedf_probe+0x5dcf/0x6bc0 [ 2.312969] kasan_report+0x4b/0x70 [ 2.312969] ? kobject_put+0x25d/0x290 [ 2.312969] kasan_check_range+0x2ca/0x310 [ 2.312969] __qedf_probe+0x5dcf/0x6bc0 [ 2.312969] ? selinux_kernfs_init_security+0xdc/0x5f0 [ 2.312969] ? trace_rpm_return_int_rcuidle+0x18/0x120 [ 2.312969] ? rpm_resume+0xa5c/0x16e0 [ 2.312969] ? qedf_get_generic_tlv_data+0x160/0x160 [ 2.312969] local_pci_probe+0x13c/0x1f0 [ 2.312969] pci_device_probe+0x37e/0x6c0 Link: https://lore.kernel.org/r/20211112120641.16073-1-fantasquex@gmail.com Reported-by: Zheyu Ma Acked-by: Saurav Kashyap Co-developed-by: Wende Tan Signed-off-by: Wende Tan Signed-off-by: Letu Ren Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/qedf/qedf_main.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/drivers/scsi/qedf/qedf_main.c b/drivers/scsi/qedf/qedf_main.c index e64457f53da8..de5b6453827c 100644 --- a/drivers/scsi/qedf/qedf_main.c +++ b/drivers/scsi/qedf/qedf_main.c @@ -3671,11 +3671,6 @@ static int __qedf_probe(struct pci_dev *pdev, int mode) err1: scsi_host_put(lport->host); err0: - if (qedf) { - QEDF_INFO(&qedf->dbg_ctx, QEDF_LOG_DISC, "Probe done.\n"); - - clear_bit(QEDF_PROBING, &qedf->flags); - } return rc; } -- 2.35.1