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[2620:137:e000::1:20]) by mx.google.com with ESMTP id g14-20020a056402180e00b0045102ae16dasi1536830edy.198.2022.10.14.01.04.31; Fri, 14 Oct 2022 01:04:56 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=antgroup.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229595AbiJNHzv (ORCPT + 99 others); Fri, 14 Oct 2022 03:55:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229733AbiJNHzs (ORCPT ); Fri, 14 Oct 2022 03:55:48 -0400 Received: from out0-140.mail.aliyun.com (out0-140.mail.aliyun.com [140.205.0.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37B2617FD51; Fri, 14 Oct 2022 00:55:46 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R191e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018047209;MF=houwenlong.hwl@antgroup.com;NM=1;PH=DS;RN=11;SR=0;TI=SMTPD_---.Pc1XjxL_1665734112; Received: from localhost(mailfrom:houwenlong.hwl@antgroup.com fp:SMTPD_---.Pc1XjxL_1665734112) by smtp.aliyun-inc.com; Fri, 14 Oct 2022 15:55:12 +0800 From: "Hou Wenlong" To: kvm@vger.kernel.org Cc: Sean Christopherson , Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Peter Xu , linux-kernel@vger.kernel.org Subject: [PATCH] KVM: x86: Reduce refcount if single_open() fails in kvm_mmu_rmaps_stat_open() Date: Fri, 14 Oct 2022 15:55:11 +0800 Message-Id: X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_HELO_NONE, SPF_PASS,UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1746649425577746657?= X-GMAIL-MSGID: =?utf-8?q?1746649425577746657?= Refcount is increased before calling single_open() in kvm_mmu_rmaps_stat_open(), If single_open() fails, refcount should be restored, otherwise the vm couldn't be destroyed. Fixes: 3bcd0662d66fd ("KVM: X86: Introduce mmu_rmaps_stat per-vm debugfs file") Signed-off-by: Hou Wenlong --- arch/x86/kvm/debugfs.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/debugfs.c b/arch/x86/kvm/debugfs.c index cfed36aba2f7..412ed1b341fa 100644 --- a/arch/x86/kvm/debugfs.c +++ b/arch/x86/kvm/debugfs.c @@ -162,7 +162,12 @@ static int kvm_mmu_rmaps_stat_open(struct inode *inode, struct file *file) if (!kvm_get_kvm_safe(kvm)) return -ENOENT; - return single_open(file, kvm_mmu_rmaps_stat_show, kvm); + if (single_open(file, kvm_mmu_rmaps_stat_show, kvm)) { + kvm_put_kvm(kvm); + return -ENOMEM; + } + + return 0; } static int kvm_mmu_rmaps_stat_release(struct inode *inode, struct file *file)