From patchwork Mon Aug 29 08:05:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 601944 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 2D7F9ECAAD5 for ; Mon, 29 Aug 2022 08:06:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229549AbiH2IGu (ORCPT ); Mon, 29 Aug 2022 04:06:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47942 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229775AbiH2IGs (ORCPT ); Mon, 29 Aug 2022 04:06:48 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 488191FCD9; Mon, 29 Aug 2022 01:06:47 -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 AE45AB80D56; Mon, 29 Aug 2022 08:06:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A595C433D7; Mon, 29 Aug 2022 08:06:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661760404; bh=KNKGIE3bHAIRg1FhRy5svzN00TPQDw3yiZKUrgewicQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XUoHJHaDPKJowsLt/nWFKf9SxrhygruA3UBkM7z5BJy4erb6YRzwUkLkQnTFsD2ki Ctxbhn+fGLuH2Lri3qI64izeRE6/cZ5zqi0YuigMolu13Ez6iKsnVXDj9NO7PaviBm b8seh2f44G0++OAyrExhnCyu+9hXAc98XA7qDrSVhZ3wrsskKyX4h7bgqRGeWNMW5C LcaBxLO88NzGhodtRdnCih0W5WcAng5RSsBtypFZbu/JAaN0u8+fcRbUouL43mXJYk Z/EVwt2mBADRPPWhDjBwc8KEvKciLh70vMqzhUWbB1V+hGtlOSykX1ubIm31LQud+J hGh7+VFgKqLaA== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1oSZnI-0007jW-3g; Mon, 29 Aug 2022 10:06:52 +0200 From: Johan Hovold To: Srinivas Kandagatla , Amol Maheshwari Cc: Greg Kroah-Hartman , Arnd Bergmann , Bjorn Andersson , Manivannan Sadhasivam , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , stable@vger.kernel.org Subject: [PATCH 2/3] misc: fastrpc: fix memory corruption on open Date: Mon, 29 Aug 2022 10:05:30 +0200 Message-Id: <20220829080531.29681-3-johan+linaro@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220829080531.29681-1-johan+linaro@kernel.org> References: <20220829080531.29681-1-johan+linaro@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org The probe session-duplication overflow check incremented the session count also when there were no more available sessions so that memory beyond the fixed-size slab-allocated session array could be corrupted in fastrpc_session_alloc() on open(). Fixes: f6f9279f2bf0 ("misc: fastrpc: Add Qualcomm fastrpc basic driver model") Cc: stable@vger.kernel.org # 5.1 Signed-off-by: Johan Hovold --- drivers/misc/fastrpc.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c index 88091778c1b8..6e312ac85668 100644 --- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -1948,7 +1948,7 @@ static int fastrpc_cb_probe(struct platform_device *pdev) spin_unlock_irqrestore(&cctx->lock, flags); return -ENOSPC; } - sess = &cctx->session[cctx->sesscount]; + sess = &cctx->session[cctx->sesscount++]; sess->used = false; sess->valid = true; sess->dev = dev; @@ -1961,13 +1961,12 @@ static int fastrpc_cb_probe(struct platform_device *pdev) struct fastrpc_session_ctx *dup_sess; for (i = 1; i < sessions; i++) { - if (cctx->sesscount++ >= FASTRPC_MAX_SESSIONS) + if (cctx->sesscount >= FASTRPC_MAX_SESSIONS) break; - dup_sess = &cctx->session[cctx->sesscount]; + dup_sess = &cctx->session[cctx->sesscount++]; memcpy(dup_sess, sess, sizeof(*dup_sess)); } } - cctx->sesscount++; spin_unlock_irqrestore(&cctx->lock, flags); rc = dma_set_mask(dev, DMA_BIT_MASK(32)); if (rc) {