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 0B4CE3368B8; Tue, 21 Jul 2026 17:37:53 +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=1784655474; cv=none; b=D8a7iGY546TNGwjZMXCcCI8F6IbNmcSnJcZOtAPj9ZOswVNACMhc2wM6on3BUkyazB/IeHxHI/wd//A2OEVyemMZU9Z9/O4TPxLJ4weGAALtiDwDBZbYmWI51XJY/96IgY7OxvvVgtUE1FJDJLo0f2wJN3jEbik1ZLv8izJppNs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784655474; c=relaxed/simple; bh=p86O9sv63ITWr764VFE9/K02WdRtiQ0iypL9X1Qc6Fc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rBpHmp0DGZbGyk+m1yFTNk8fm09Ji+ECCLQA0IHXYV2I70f2cXfD+daw7Xig+aZ9NvkK9sNjSb36BkugI/98oT9oick89OhbSOOFBcpNToFA3ID9+UFb95NVSvMeVgLQ2H2FsB17nFENvEU61UYRVTSR4jgPT+FLhxu58MUe2Wc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hYMl+4BR; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hYMl+4BR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 64ECB1F000E9; Tue, 21 Jul 2026 17:37:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784655472; bh=rcMlRaoqvKLnwEKar0Xmzm5h3JowcV2kF0pKxEzJc50=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=hYMl+4BRyMmOpbLObMuF0TQQSjz8zAybFH+AIWptLAU4S344iB9blP3R4GcpxJn52 Cj4+0iJlP3MBsdvjoIL2jKiAEADAdfChrJPOiJNABoWo2fY87AlyWU4KZD3Ty/W6rc Xg3cWx7YuSZULkoYKW5zUwG/2ivXs5PbRbzON3HM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hyunwoo Kim , Fuad Tabba , Marc Zyngier , Fuad Tabba , Sasha Levin Subject: [PATCH 6.18 0005/1611] KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU Date: Tue, 21 Jul 2026 17:02:01 +0200 Message-ID: <20260721152514.894418728@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152514.750365251@linuxfoundation.org> References: <20260721152514.750365251@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hyunwoo Kim commit 8cc8bbbfab14c22c5551d0dd19b208a44b141c76 upstream. flush_hyp_vcpu() copies the host vGIC state into the hyp's private vCPU on every run. The vGIC list register save and restore use used_lrs as their loop bound and expect it to stay within the number of implemented list registers. While this is generally the case, flush_hyp_vcpu() copies vgic_v3 verbatim and does not enforce this, so a value provided by the host is used at EL2 to index vgic_lr[] and access ICH_LR_EL2 (host -> EL2). Fix by clamping used_lrs to the number of implemented list registers after the copy, as the trusted path already does in vgic_flush_lr_state(). The number of implemented list registers is constant after init, so it is replicated once from kvm_vgic_global_state.nr_lr into hyp_gicv3_nr_lr rather than read on every entry. Cc: stable@vger.kernel.org Fixes: be66e67f1750 ("KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()") Signed-off-by: Hyunwoo Kim Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Link: https://patch.msgid.link/20260606175614.83273-3-imv4bel@gmail.com Signed-off-by: Marc Zyngier [ tabba: adjust context in flush_hyp_vcpu() and kvm_hyp.h ] Signed-off-by: Fuad Tabba Signed-off-by: Sasha Levin --- arch/arm64/include/asm/kvm_hyp.h | 1 + arch/arm64/kvm/arm.c | 2 ++ arch/arm64/kvm/hyp/nvhe/hyp-main.c | 9 +++++++++ 3 files changed, 12 insertions(+) diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h index e6be1f5d0967f6..8020e91b536d26 100644 --- a/arch/arm64/include/asm/kvm_hyp.h +++ b/arch/arm64/include/asm/kvm_hyp.h @@ -146,5 +146,6 @@ extern u64 kvm_nvhe_sym(id_aa64smfr0_el1_sys_val); extern unsigned long kvm_nvhe_sym(__icache_flags); extern unsigned int kvm_nvhe_sym(kvm_arm_vmid_bits); extern unsigned int kvm_nvhe_sym(kvm_host_sve_max_vl); +extern unsigned int kvm_nvhe_sym(hyp_gicv3_nr_lr); #endif /* __ARM64_KVM_HYP_H__ */ diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index e59cb36b5f36f3..10fc6783cd608a 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -2311,6 +2311,8 @@ static int __init init_subsystems(void) switch (err) { case 0: vgic_present = true; + if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) + kvm_nvhe_sym(hyp_gicv3_nr_lr) = kvm_vgic_global_state.nr_lr; break; case -ENODEV: case -ENXIO: diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 3dda50391446d9..6e7547b7ca432a 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -22,6 +22,9 @@ DEFINE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params); +/* Number of implemented GICv3 LRs. Used by flush_hyp_vcpu(). */ +unsigned int hyp_gicv3_nr_lr; + void __kvm_hyp_host_forward_smc(struct kvm_cpu_context *host_ctxt); static void __hyp_sve_save_guest(struct kvm_vcpu *vcpu) @@ -139,6 +142,12 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) hyp_vcpu->vcpu.arch.vsesr_el2 = host_vcpu->arch.vsesr_el2; hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3; + + /* Bound used_lrs by the number of implemented list registers. */ + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs = + min_t(unsigned int, + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs, + hyp_gicv3_nr_lr); } static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) -- 2.53.0