From patchwork Tue Mar 18 10:58:58 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: gerben@altlinux.org X-Patchwork-Id: 14020782 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 79D6FC28B28 for ; Tue, 18 Mar 2025 11:00:08 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tuUfZ-0003ou-GO; Tue, 18 Mar 2025 06:59:37 -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 1tuUfU-0003oa-Vz for qemu-devel@nongnu.org; Tue, 18 Mar 2025 06:59:33 -0400 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 1tuUfT-0003rv-4e for qemu-devel@nongnu.org; Tue, 18 Mar 2025 06:59:32 -0400 Received: from boringlust.malta.altlinux.ru (obninsk.basealt.ru [217.15.195.17]) (Authenticated sender: rastyoginds) by air.basealt.ru (Postfix) with ESMTPSA id 20F11233C0; Tue, 18 Mar 2025 13:59:27 +0300 (MSK) From: gerben@altlinux.org To: qemu-devel@nongnu.org, kwolf@redhat.com, hreitz@redhat.com Cc: sdl.qemu@linuxtesting.org Subject: [PATCH] qcow2: fix null pointer dereference in crypto block Date: Tue, 18 Mar 2025 13:58:58 +0300 Message-ID: <20250318105924.258014-1-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: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Denis Rastyogin This error was discovered by fuzzing qemu-img. The qcow2_refresh_limits() is missing a check for the s->crypto pointer, which can lead to a null pointer dereference. This commit adds the necessary check. Reported-by: Leonid Reviakin Signed-off-by: Denis Rastyogin --- block/qcow2.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/block/qcow2.c b/block/qcow2.c index dd6bcafbd8..55861a285a 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1978,6 +1978,10 @@ static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp) if (bs->encrypted) { /* Encryption works on a sector granularity */ + if (!s->crypto) { + error_setg(errp, "Encryption context is missing"); + return; + } bs->bl.request_alignment = qcrypto_block_get_sector_size(s->crypto); } bs->bl.pwrite_zeroes_alignment = s->subcluster_size;