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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,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 9BD42C47240 for ; Mon, 24 May 2021 16:04:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78340613E6 for ; Mon, 24 May 2021 16:04:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236926AbhEXQEo (ORCPT ); Mon, 24 May 2021 12:04:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:40490 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234644AbhEXP6L (ORCPT ); Mon, 24 May 2021 11:58:11 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 191A36195B; Mon, 24 May 2021 15:44:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621871046; bh=nb5gPHQ0lc71Pv8hxVx6JmpASmurqXzUg7X9LXFRH3k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jrUFbH4pfx6eO8PIxAZSeAESaV/PP4oRu14hmh98RPir2OStr5llSFrErFj30bjN+ R/s4JiCtL1zPNkUO+lndtzrGgSDBhgpvCjmJ0UGPPh8DjWkMAqRX7B2Nma5hOJOIT6 XbvuHQ18R/otvPjR4sXKguiD218MyRhZzobogOAE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lv Yunlong , Oded Gabbay , Sasha Levin Subject: [PATCH 5.12 004/127] habanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory Date: Mon, 24 May 2021 17:25:21 +0200 Message-Id: <20210524152335.006868701@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210524152334.857620285@linuxfoundation.org> References: <20210524152334.857620285@linuxfoundation.org> User-Agent: quilt/0.66 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: Lv Yunlong [ Upstream commit 115726c5d312b462c9d9931ea42becdfa838a076 ] Our code analyzer reported a uaf. In gaudi_memset_device_memory, cb is get via hl_cb_kernel_create() with 2 refcount. If hl_cs_allocate_job() failed, the execution runs into release_cb branch. One ref of cb is dropped by hl_cb_put(cb) and could be freed if other thread also drops one ref. Then cb is used by cb->id later, which is a potential uaf. My patch add a variable 'id' to accept the value of cb->id before the hl_cb_put(cb) is called, to avoid the potential uaf. Fixes: 423815bf02e25 ("habanalabs/gaudi: remove PCI access to SM block") Signed-off-by: Lv Yunlong Reviewed-by: Oded Gabbay Signed-off-by: Oded Gabbay Signed-off-by: Sasha Levin --- drivers/misc/habanalabs/gaudi/gaudi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/misc/habanalabs/gaudi/gaudi.c b/drivers/misc/habanalabs/gaudi/gaudi.c index 9152242778f5..ecdedd87f8cc 100644 --- a/drivers/misc/habanalabs/gaudi/gaudi.c +++ b/drivers/misc/habanalabs/gaudi/gaudi.c @@ -5546,6 +5546,7 @@ static int gaudi_memset_device_memory(struct hl_device *hdev, u64 addr, struct hl_cs_job *job; u32 cb_size, ctl, err_cause; struct hl_cb *cb; + u64 id; int rc; cb = hl_cb_kernel_create(hdev, PAGE_SIZE, false); @@ -5612,8 +5613,9 @@ static int gaudi_memset_device_memory(struct hl_device *hdev, u64 addr, } release_cb: + id = cb->id; hl_cb_put(cb); - hl_cb_destroy(hdev, &hdev->kernel_cb_mgr, cb->id << PAGE_SHIFT); + hl_cb_destroy(hdev, &hdev->kernel_cb_mgr, id << PAGE_SHIFT); return rc; } -- 2.30.2