From patchwork Thu Dec 12 20:40:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: gerben@altlinux.org X-Patchwork-Id: 13905958 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 081BCE7717F for ; Thu, 12 Dec 2024 20:41:14 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tLpzS-00018c-G3; Thu, 12 Dec 2024 15:40:54 -0500 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 1tLpzQ-000189-OV for qemu-devel@nongnu.org; Thu, 12 Dec 2024 15:40:52 -0500 Received: from air.basealt.ru ([193.43.8.18]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tLpzO-0008HB-N1 for qemu-devel@nongnu.org; Thu, 12 Dec 2024 15:40:52 -0500 Received: from localhost.localdomain (unknown [128.204.73.216]) by air.basealt.ru (Postfix) with ESMTPSA id 7796523397; Thu, 12 Dec 2024 23:40:45 +0300 (MSK) From: gerben@altlinux.org To: richard.henderson@linaro.org, fred.konrad@greensocs.com, qemu-devel@nongnu.org Cc: sdl.qemu@linuxtesting.org, Denis Rastyogin , David Meliksetyan Subject: [PATCH v3] hw/display: refine upper limit for offset value in assert check Date: Thu, 12 Dec 2024 23:40:29 +0300 Message-ID: <20241212204041.529835-1-gerben@altlinux.org> X-Mailer: git-send-email 2.42.2 MIME-Version: 1.0 Received-SPF: pass client-ip=193.43.8.18; envelope-from=gerben@altlinux.org; helo=air.basealt.ru X-Spam_score_int: 14 X-Spam_score: 1.4 X-Spam_bar: + X-Spam_report: (1.4 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_SBL_CSS=3.335, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Denis Rastyogin Accessing an element of the s->core_registers array, which has a size of 236 (0x3AC), may lead to a buffer overflow if the 'offset' index exceeds the valid range, potentially reaching values up to 5139 (0x504C >> 2). The bounds check has been extended to DP_CORE_REG_ARRAY_SIZE (0x3B0 >> 2) to ensure the offset remains within the valid range before writing data. The memory region is registered to match the size of the core_registers array. This ensures that the guest cannot issue an out-of-bounds write. Therefore, using `assert` remains appropriate to catch internal violations. Found by Linux Verification Center (linuxtesting.org) with SVACE. Reported-by: David Meliksetyan Signed-off-by: Denis Rastyogin --- hw/display/xlnx_dp.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/hw/display/xlnx_dp.c b/hw/display/xlnx_dp.c index 6ab2335499..3f1f5d81bd 100644 --- a/hw/display/xlnx_dp.c +++ b/hw/display/xlnx_dp.c @@ -896,7 +896,11 @@ static void xlnx_dp_write(void *opaque, hwaddr offset, uint64_t value, xlnx_dp_update_irq(s); break; default: - assert(offset <= (0x504C >> 2)); + /* + * Check to ensure the offset is within the bounds of + * the core_registers[] array. + */ + assert(offset < DP_CORE_REG_ARRAY_SIZE); s->core_registers[offset] = value; break; }