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 X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B223C433E1 for ; Fri, 21 Aug 2020 17:20:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D00612054F for ; Fri, 21 Aug 2020 17:20:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598030452; bh=0fVKRcxzaOhqKpTZuNkdyaVVibqDGakKkUCMuuKRGMk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=u2CakShAmr3dI7MJJE3HnA47SvN1eOgSed3J/dCCleJjr5976vnTqEdyGazNYtDrp iimj7OE2qH5jXQElPlejNWlN2Urp6GFTCL25Vkd1Ba0xqnSTivVcWEekw1Rn4UBB0I VeFEyDlk+VeyD+1iAcxBwjRsCqyOXc7C5PklBdds= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728209AbgHURUu (ORCPT ); Fri, 21 Aug 2020 13:20:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:48870 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728043AbgHUQQH (ORCPT ); Fri, 21 Aug 2020 12:16:07 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B72D420578; Fri, 21 Aug 2020 16:16:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598026566; bh=0fVKRcxzaOhqKpTZuNkdyaVVibqDGakKkUCMuuKRGMk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EEtDT6z7zzkxUxd2WRLQLETChSMMODA53QA37xwWSqFc5CyAbfVOubbUNkevKLjVX Y97KhtPbw2ctxIamQpO7Bml4cWBNow6/w7ZuOvsMorhvsSySP8k3XxqPFAMUW8pD7z kKmK2iYtH/5m/J1ileNh4rKpDZ1rCli6Cw8Hqjak= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Bodo Stroesser , JiangYu , Mike Christie , "Martin K . Petersen" , Sasha Levin , linux-scsi@vger.kernel.org, target-devel@vger.kernel.org Subject: [PATCH AUTOSEL 5.7 17/61] scsi: target: tcmu: Fix crash on ARM during cmd completion Date: Fri, 21 Aug 2020 12:15:01 -0400 Message-Id: <20200821161545.347622-17-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200821161545.347622-1-sashal@kernel.org> References: <20200821161545.347622-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Bodo Stroesser [ Upstream commit 5a0c256d96f020e4771f6fd5524b80f89a2d3132 ] If tcmu_handle_completions() has to process a padding shorter than sizeof(struct tcmu_cmd_entry), the current call to tcmu_flush_dcache_range() with sizeof(struct tcmu_cmd_entry) as length param is wrong and causes crashes on e.g. ARM, because tcmu_flush_dcache_range() in this case calls flush_dcache_page(vmalloc_to_page(start)); with start being an invalid address above the end of the vmalloc'ed area. The fix is to use the minimum of remaining ring space and sizeof(struct tcmu_cmd_entry) as the length param. The patch was tested on kernel 4.19.118. See https://bugzilla.kernel.org/show_bug.cgi?id=208045#c10 Link: https://lore.kernel.org/r/20200629093756.8947-1-bstroesser@ts.fujitsu.com Tested-by: JiangYu Acked-by: Mike Christie Signed-off-by: Bodo Stroesser Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/target/target_core_user.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index b63a1e0c4aa6d..b64ed7dbaa68a 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -1220,7 +1220,14 @@ static unsigned int tcmu_handle_completions(struct tcmu_dev *udev) struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned; - tcmu_flush_dcache_range(entry, sizeof(*entry)); + /* + * Flush max. up to end of cmd ring since current entry might + * be a padding that is shorter than sizeof(*entry) + */ + size_t ring_left = head_to_end(udev->cmdr_last_cleaned, + udev->cmdr_size); + tcmu_flush_dcache_range(entry, ring_left < sizeof(*entry) ? + ring_left : sizeof(*entry)); if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD) { UPDATE_HEAD(udev->cmdr_last_cleaned, -- 2.25.1