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[104.155.91.135]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-46508a0546fsm418554f8f.2.2026.06.18.10.14.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Jun 2026 10:14:35 -0700 (PDT) Date: Thu, 18 Jun 2026 18:14:32 +0100 From: Vincent Donnefort To: Sebastian Ene Cc: catalin.marinas@arm.com, oupton@kernel.org, sudeep.holla@kernel.org, will@kernel.org, jens.wiklander@linaro.org, joey.gouly@arm.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, android-kvm@google.com, maz@kernel.org, mrigendra.chaubey@gmail.com, op-tee@lists.trustedfirmware.org, perlarsen@google.com, seiden@linux.ibm.com, smostafa@google.com, sumit.garg@kernel.org, suzuki.poulose@arm.com, yuzenghui@huawei.com, Sashiko AI Subject: Re: [PATCH v7 7/7] KVM: arm64: Zero out the stack initialized data in the FFA handler Message-ID: References: <20260617145130.3729015-1-sebastianene@google.com> <20260617145130.3729015-8-sebastianene@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260617145130.3729015-8-sebastianene@google.com> On Wed, Jun 17, 2026 at 02:51:30PM +0000, Sebastian Ene wrote: > Don't leak hypervisor stack data when using the FFA_VERSION call. > When the compiler doesn't support -ftrivial-auto-var-init=zero option Even when it does, I believe this is an optional kernel option. > we need to zero out the stack initialized variable before returning data > to the host caller. > > Reported-by: Sashiko AI It seems most people are using "Reported-by: Sashiko " > Closes: > https://lore.kernel.org/all/20260616160016.C62C81F000E9@smtp.kernel.org/ > Fixes: c9c012625e12 ("KVM: arm64: Trap FFA_VERSION host call in pKVM") > Signed-off-by: Sebastian Ene Reviewed-by: Vincent Donnefort > --- > arch/arm64/kvm/hyp/nvhe/ffa.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c > index d7c5701d0584..b321682ead04 100644 > --- a/arch/arm64/kvm/hyp/nvhe/ffa.c > +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c > @@ -883,7 +883,7 @@ static void do_ffa_part_get(struct arm_smccc_1_2_regs *res, > > bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id) > { > - struct arm_smccc_1_2_regs res; > + struct arm_smccc_1_2_regs res = {0}; > > /* > * There's no way we can tell what a non-standard SMC call might > -- > 2.54.0.1136.gdb2ca164c4-goog >