linux-kernel - [PATCH v2 1/2] KVM: arm64: Fix enforcement of upper bound on MDCR

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250709093808.920284-2-ben.horgan@arm.com>
Date: Wed,  9 Jul 2025 10:38:07 +0100
From: Ben Horgan <ben.horgan@....com>
To: catalin.marinas@....com,
	will@...nel.org,
	maz@...nel.org,
	oliver.upton@...ux.dev,
	joey.gouly@....com,
	suzuki.poulose@....com,
	yuzenghui@...wei.com,
	linux-arm-kernel@...ts.infradead.org,
	kvmarm@...ts.linux.dev,
	yury.norov@...il.com,
	linux@...musvillemoes.dk,
	linux-kernel@...r.kernel.org
Cc: james.morse@....com,
	Ben Horgan <ben.horgan@....com>,
	stable@...r.kernel.org
Subject: [PATCH v2 1/2] KVM: arm64: Fix enforcement of upper bound on MDCR_EL2.HPMN

Previously, u64_replace_bits() was used to no effect as the return value
was ignored. Convert to u64p_replace_bits() so the value is updated in
place.

Reviewed-by: Zenghui Yu <yuzenghui@...wei.com>
Signed-off-by: Ben Horgan <ben.horgan@....com>
Fixes: efff9dd2fee7 ("KVM: arm64: Handle out-of-bound write to MDCR_EL2.HPMN")
Cc: Marc Zyngier <maz@...nel.org>
Cc: stable@...r.kernel.org
---
 arch/arm64/kvm/sys_regs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 76c2f0da821f..c20bd6f21e60 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2624,7 +2624,7 @@ static bool access_mdcr(struct kvm_vcpu *vcpu,
 	 */
 	if (hpmn > vcpu->kvm->arch.nr_pmu_counters) {
 		hpmn = vcpu->kvm->arch.nr_pmu_counters;
-		u64_replace_bits(val, hpmn, MDCR_EL2_HPMN);
+		u64p_replace_bits(&val, hpmn, MDCR_EL2_HPMN);
 	}
 
 	__vcpu_assign_sys_reg(vcpu, MDCR_EL2, val);
-- 
2.43.0