From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7029F51AFCD for ; Tue, 22 Sep 2026 21:42:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790113359; cv=none; b=j23y9FjkzI9XFiG/uIgP/NbiPbCIKvZwaPAoM18Z1ZvejOJSi8D4nYbf8kTk72hkNJY/tQkcjXIhgnPtGgeSdvLOffD76VBMu/f/vRtsD9qydvUQ6W7d3pl3w02I1dT3eUXuURSH8xSdA+/mZcwsy46dWi3V7h1oFaftnISMngo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790113359; c=relaxed/simple; bh=12JRLMh/M6XOSou8Mysqo3VtOfUZh7uz6UjK+EWC+lg=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=bRbJh2EYfv9G9Sy+ATrx+w1MZqw7PVaYaN3vCKRXoRFSiKvHkUQS4kPz+g88uE2hDp+eWXZOAvFne+TLk/gEwoM7q7QX54KzFXnKvWOYJ5XVumYrge0ma93Msw7UVhIgm03ZUvvRmGK1ZsTsEsxreWDL2hx14RFXzEOKx/p2kmQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=esjP7qAa; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="esjP7qAa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B717C1F000FF; Tue, 22 Sep 2026 21:42:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790113344; bh=6rXdzRPRFaAkzJK2CTbotf/X0PgO5pvJQVZtTI8XXN4=; h=From:To:Cc:Subject:Date; b=esjP7qAaLzUReZuUkYkPuocF/yKfoJxpuO0zFP9b3dxw4ydnOI1aEZzI7EOLOKs8O V9/trT+ZtO3X2bVXgc7+SoOEKd8RWDlbg/rPOBqyvOlT/KJM1mkOTlJo8hdJtm/91O hOpf8olk23q1yQtTDvHNYJkZ++BBuKfiiQ2uDOhpeOysm/QG01zLDqTAsVWEkC7aU2 2WSGEwCRIHPC+1ApnXsijAvmshnwgF77BrHUUqou6mmceN44RU9homJK3CfkfWJarO f7wSfZAQfi9oq2MjKSjxjxaw4wuerk406DH6s7YebmqCLEvO/oMk+0yF2wYe+hj2M+ xAezx+rJD8tlQ== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1x98Fq-0000000CFxJ-1mQv; Tue, 22 Sep 2026 21:42:22 +0000 From: Marc Zyngier To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: Steffen Eiden , Joey Gouly , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Fuad Tabba , Yuchao Zhang Subject: [PATCH 0/3] KVM: arm64: vgic-v3: Make LPI disabling robust Date: Tue, 22 Sep 2026 22:42:09 +0100 Message-ID: <20260922214212.3327146-1-maz@kernel.org> X-Mailer: git-send-email 2.47.3 Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, seiden@linux.ibm.com, joey.gouly@arm.com, suzuki.poulose@arm.com, oupton@kernel.org, yuzenghui@huawei.com, fuad.tabba@linux.dev, ndaugoing@gmail.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Yuchao Zhang reported that disabling LPIs on one CPU from another could result in UAFs and other horrors. There are two reasons for this: - the last_lr_irq pointer does not contribute to LPI refcount, and that LPI being removed results in a dangling pointer - LPIs can be deleted from a remote vcpu by disabling them while that vcpu is actually running, and has LPIs in its LRs. Address the two issues in one go, by actively taking a refcount on all IRQs referenced by last_lr_irq, and making sure that disabling LPIs force all vcpus to be paused, making it safe. Marc Zyngier (3): KVM: arm64: vgic: Allow last_lr_irq to be NULL when LRs are not overflowing KVM: arm64: vgic: Take a refcount on IRQs referenced by last_lr_irq KVM: arm64: vgic: Stop the VM when disabling LPIs arch/arm64/kvm/vgic/vgic-mmio-v3.c | 10 ++++++++++ arch/arm64/kvm/vgic/vgic-v2.c | 6 ++++-- arch/arm64/kvm/vgic/vgic-v3.c | 6 ++++-- arch/arm64/kvm/vgic/vgic.c | 21 ++++++++++++++++----- 4 files changed, 34 insertions(+), 9 deletions(-) -- 2.47.3