From patchwork Wed Oct 4 08:02:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 1843064 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4S0nTs1bXhz20cv for ; Wed, 4 Oct 2023 19:12:01 +1100 (AEDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qnwvp-0002A9-S7; Wed, 04 Oct 2023 04:08:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qnwu8-0006UT-5b; Wed, 04 Oct 2023 04:06:49 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qnwu5-0003ji-Na; Wed, 04 Oct 2023 04:06:47 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id DF213275B9; Wed, 4 Oct 2023 11:02:31 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id 388682CBF2; Wed, 4 Oct 2023 11:02:31 +0300 (MSK) Received: (nullmailer pid 2702883 invoked by uid 1000); Wed, 04 Oct 2023 08:02:22 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Mark Cave-Ayland , Thomas Huth , Paolo Bonzini , Michael Tokarev Subject: [Stable-8.1.2 44/45] esp: restrict non-DMA transfer length to that of available data Date: Wed, 4 Oct 2023 11:02:05 +0300 Message-Id: <20231004080221.2702636-44-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Mark Cave-Ayland In the case where a SCSI layer transfer is incorrectly terminated, it is possible for a TI command to cause a SCSI buffer overflow due to the expected transfer data length being less than the available data in the FIFO. When this occurs the unsigned async_len variable underflows and becomes a large offset which writes past the end of the allocated SCSI buffer. Restrict the non-DMA transfer length to be the smallest of the expected transfer length and the available FIFO data to ensure that it is no longer possible for the SCSI buffer overflow to occur. Signed-off-by: Mark Cave-Ayland Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1810 Reviewed-by: Thomas Huth Message-ID: <20230913204410.65650-3-mark.cave-ayland@ilande.co.uk> Signed-off-by: Paolo Bonzini (cherry picked from commit 77668e4b9bca03a856c27ba899a2513ddf52bb52) Signed-off-by: Michael Tokarev diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c index 4218a6a960..9b11d8c573 100644 --- a/hw/scsi/esp.c +++ b/hw/scsi/esp.c @@ -759,7 +759,8 @@ static void esp_do_nodma(ESPState *s) } if (to_device) { - len = MIN(fifo8_num_used(&s->fifo), ESP_FIFO_SZ); + len = MIN(s->async_len, ESP_FIFO_SZ); + len = MIN(len, fifo8_num_used(&s->fifo)); esp_fifo_pop_buf(&s->fifo, s->async_buf, len); s->async_buf += len; s->async_len -= len;