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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 90524C4338F for ; Wed, 18 Aug 2021 12:49:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7022661076 for ; Wed, 18 Aug 2021 12:49:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236388AbhHRMuB (ORCPT ); Wed, 18 Aug 2021 08:50:01 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:8039 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234949AbhHRMt7 (ORCPT ); Wed, 18 Aug 2021 08:49:59 -0400 Received: from dggeme766-chm.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4GqSQ213zmzYcrJ; Wed, 18 Aug 2021 20:48:58 +0800 (CST) Received: from huawei.com (10.175.104.82) by dggeme766-chm.china.huawei.com (10.3.19.112) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Wed, 18 Aug 2021 20:49:21 +0800 From: Wang Hai To: , , , , , , CC: , Subject: [PATCH v2] VMCI: fix NULL pointer dereference when unmapping queue pair Date: Wed, 18 Aug 2021 20:48:45 +0800 Message-ID: <20210818124845.488312-1-wanghai38@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.104.82] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggeme766-chm.china.huawei.com (10.3.19.112) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I got a NULL pointer dereference report when doing fuzz test: Call Trace: qp_release_pages+0xae/0x130 qp_host_unregister_user_memory.isra.25+0x2d/0x80 vmci_qp_broker_unmap+0x191/0x320 ? vmci_host_do_alloc_queuepair.isra.9+0x1c0/0x1c0 vmci_host_unlocked_ioctl+0x59f/0xd50 ? do_vfs_ioctl+0x14b/0xa10 ? tomoyo_file_ioctl+0x28/0x30 ? vmci_host_do_alloc_queuepair.isra.9+0x1c0/0x1c0 __x64_sys_ioctl+0xea/0x120 do_syscall_64+0x34/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xae When a queue pair is created by the following call, it will not register the user memory if the page_store is NULL, and the entry->state will be set to VMCIQPB_CREATED_NO_MEM. vmci_host_unlocked_ioctl vmci_host_do_alloc_queuepair vmci_qp_broker_alloc qp_broker_alloc qp_broker_create // set entry->state = VMCIQPB_CREATED_NO_MEM; When unmapping this queue pair, qp_host_unregister_user_memory() will be called to unregister the non-existent user memory, which will result in a null pointer reference. It will also change VMCIQPB_CREATED_NO_MEM to VMCIQPB_CREATED_MEM, which should not be present in this operation. Only when the qp broker has mem, it can unregister the user memory when unmapping the qp broker. Only when the qp broker has no mem, it can register the user memory when mapping the qp broker. Fixes: 06164d2b72aa ("VMCI: queue pairs implementation.") Reported-by: Hulk Robot Signed-off-by: Wang Hai --- v1->v2: fix bug in vmci_qp_broker_map drivers/misc/vmw_vmci/vmci_queue_pair.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c index 880c33ab9f47..94ebf7f3fd58 100644 --- a/drivers/misc/vmw_vmci/vmci_queue_pair.c +++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c @@ -2243,7 +2243,8 @@ int vmci_qp_broker_map(struct vmci_handle handle, result = VMCI_SUCCESS; - if (context_id != VMCI_HOST_CONTEXT_ID) { + if (context_id != VMCI_HOST_CONTEXT_ID && + !QPBROKERSTATE_HAS_MEM(entry)) { struct vmci_qp_page_store page_store; page_store.pages = guest_mem; @@ -2350,7 +2351,8 @@ int vmci_qp_broker_unmap(struct vmci_handle handle, goto out; } - if (context_id != VMCI_HOST_CONTEXT_ID) { + if (context_id != VMCI_HOST_CONTEXT_ID && + QPBROKERSTATE_HAS_MEM(entry)) { qp_acquire_queue_mutex(entry->produce_q); result = qp_save_headers(entry); if (result < VMCI_SUCCESS) -- 2.17.1