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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F35B8C433EF for ; Wed, 6 Oct 2021 11:13:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DAE0761100 for ; Wed, 6 Oct 2021 11:13:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238486AbhJFLPY (ORCPT ); Wed, 6 Oct 2021 07:15:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:38464 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238452AbhJFLOp (ORCPT ); Wed, 6 Oct 2021 07:14:45 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8C88F610E5; Wed, 6 Oct 2021 11:12:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1633518773; bh=S0KH+J6vMXprgUfxZ2iKsZNoafSJEg3a3AuCU8wUOHQ=; h=From:To:Cc:Subject:Date:From; b=TCsQeI835bGoZcGyWjvmUzeqgISCcBqkAXU15iWhnEdqcwCjYqyCOxeOspfmNIGXn 2BcpFoaRSPggpXGujVYztRYns7b4bHPcJWc7j3FFV89aWpoAPfGvA8Lk86VzBwMmd0 7J1jmwh8xlv9oUxf/hTfccFrIyyg2++Kbet3qnZVnbLe+RrnRGj8OrrNx33zcW9wpi gUyDuZmFLWyZ46qvOm3ZZTB3lBQqeu3jaGJg5qvVKwGKPxRFk/FDVjMczwXzC9BVEu nKl01Kssf7edv61ZJBwrXJvZbE3wm5gEGovvMNX68YWOgtAU1hJrPhx61eWblD2iqx u/a0meUDdNXJQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Haimin Zhang , TCS Robot , Paolo Bonzini , Sasha Levin , tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, kvm@vger.kernel.org Subject: [PATCH MANUALSEL 5.4 1/4] KVM: x86: Handle SRCU initialization failure during page track init Date: Wed, 6 Oct 2021 07:12:47 -0400 Message-Id: <20211006111250.264294-1-sashal@kernel.org> X-Mailer: git-send-email 2.33.0 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Haimin Zhang [ Upstream commit eb7511bf9182292ef1df1082d23039e856d1ddfb ] Check the return of init_srcu_struct(), which can fail due to OOM, when initializing the page track mechanism. Lack of checking leads to a NULL pointer deref found by a modified syzkaller. Reported-by: TCS Robot Signed-off-by: Haimin Zhang Message-Id: <1630636626-12262-1-git-send-email-tcs_kernel@tencent.com> [Move the call towards the beginning of kvm_arch_init_vm. - Paolo] Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/x86/include/asm/kvm_page_track.h | 2 +- arch/x86/kvm/page_track.c | 4 ++-- arch/x86/kvm/x86.c | 7 ++++++- 3 files changed, 9 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h index 172f9749dbb2..5986bd4aacd6 100644 --- a/arch/x86/include/asm/kvm_page_track.h +++ b/arch/x86/include/asm/kvm_page_track.h @@ -46,7 +46,7 @@ struct kvm_page_track_notifier_node { struct kvm_page_track_notifier_node *node); }; -void kvm_page_track_init(struct kvm *kvm); +int kvm_page_track_init(struct kvm *kvm); void kvm_page_track_cleanup(struct kvm *kvm); void kvm_page_track_free_memslot(struct kvm_memory_slot *free, diff --git a/arch/x86/kvm/page_track.c b/arch/x86/kvm/page_track.c index 3521e2d176f2..ef89a3ede425 100644 --- a/arch/x86/kvm/page_track.c +++ b/arch/x86/kvm/page_track.c @@ -167,13 +167,13 @@ void kvm_page_track_cleanup(struct kvm *kvm) cleanup_srcu_struct(&head->track_srcu); } -void kvm_page_track_init(struct kvm *kvm) +int kvm_page_track_init(struct kvm *kvm) { struct kvm_page_track_notifier_head *head; head = &kvm->arch.track_notifier_head; - init_srcu_struct(&head->track_srcu); INIT_HLIST_HEAD(&head->track_notifier_list); + return init_srcu_struct(&head->track_srcu); } /* diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f1a0eebdcf64..69e286edb2c9 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9585,9 +9585,15 @@ void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) { + int ret; + if (type) return -EINVAL; + ret = kvm_page_track_init(kvm); + if (ret) + return ret; + INIT_HLIST_HEAD(&kvm->arch.mask_notifier_list); INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); @@ -9614,7 +9620,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) INIT_DELAYED_WORK(&kvm->arch.kvmclock_sync_work, kvmclock_sync_fn); kvm_hv_init_vm(kvm); - kvm_page_track_init(kvm); kvm_mmu_init_vm(kvm); return kvm_x86_ops->vm_init(kvm); -- 2.33.0