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(unknown [36.110.52.2]) by APP-05 (Coremail) with SMTP id zQCowABH1QiyQ99pSIKTDQ--.36677S2; Wed, 15 Apr 2026 15:52:18 +0800 (CST) From: Jiakai Xu To: kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Cc: Albert Ou , Alexandre Ghiti , Andrew Jones , Anup Patel , Atish Patra , Palmer Dabbelt , Paul Walmsley , Jiakai Xu , Jiakai Xu Subject: [PATCH] RISC-V: KVM: Fix invalid HVA warning in steal-time recording Date: Wed, 15 Apr 2026 07:52:16 +0000 Message-Id: <20260415075216.2757427-1-xujiakai2025@iscas.ac.cn> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: zQCowABH1QiyQ99pSIKTDQ--.36677S2 X-Coremail-Antispam: 1UD129KBjvJXoW7CF15Kr48ur1UKw13Jr4fXwb_yoW8AF15pF ZrCr98Ww1rtry2gasrAr4kWa1jg3yvgF1qgr9I9F90yrs0kFyYyrsYk34IvFyUJry0qF1r ZF1YqF1Duan8AFJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBI14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26ryj6F1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVWxJr0_GcWl84ACjcxK6I8E87Iv6xkF7I0E14v26r xl6s0DM2vYz4IE04k24VAvwVAKI4IrM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVAC Y4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJV W8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI2 0VAGYxC7M4IIrI8v6xkF7I0E8cxan2IY04v7MxkF7I0En4kS14v26r1q6r43MxAIw28Icx kI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2Iq xVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42 IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY 6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aV CY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUbQVy7UUUUU== X-CM-SenderInfo: 50xmxthndljiysv6x2xfdvhtffof0/1tbiBg0SCWnfJvJ8DgAAsA Content-Type: text/plain; charset="utf-8" kvm_riscv_vcpu_record_steal_time() assumes that the steal-time shared memory GPA (vcpu->arch.sta.shmem) is always backed by a valid guest memory slot. However, this assumption is not guaranteed by the KVM userspace ABI. A malicious or buggy userspace can set the STA shared memory GPA via KVM_SET_ONE_REG without establishing a corresponding memory region via KVM_SET_USER_MEMORY_REGION. In such cases, the GPA cannot be translated to a valid HVA and kvm_vcpu_gfn_to_hva() returns an error address. The current implementation incorrectly treats this as a kernel warning using WARN_ON(), which may escalate to a kernel panic when panic_on_warn is enabled. This is not a kernel bug condition but a normal invalid configuration from userspace, and should be handled gracefully. Fix it by removing WARN_ON() and treating invalid HVA as a normal failure case, resetting the STA shared memory state. Fixes: e9f12b5fff8ad0 ("RISC-V: KVM: Implement SBI STA extension") Signed-off-by: Jiakai Xu Signed-off-by: Jiakai Xu Assisted-by: OpenClaw:DeepSeek-V3.2 Reviewed-by: Andrew Jones --- arch/riscv/kvm/vcpu_sbi_sta.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kvm/vcpu_sbi_sta.c b/arch/riscv/kvm/vcpu_sbi_sta.c index 3b834709b429f..60e50296a0085 100644 --- a/arch/riscv/kvm/vcpu_sbi_sta.c +++ b/arch/riscv/kvm/vcpu_sbi_sta.c @@ -46,7 +46,7 @@ void kvm_riscv_vcpu_record_steal_time(struct kvm_vcpu *vc= pu) gfn =3D shmem >> PAGE_SHIFT; hva =3D kvm_vcpu_gfn_to_hva(vcpu, gfn); =20 - if (WARN_ON(kvm_is_error_hva(hva))) { + if (kvm_is_error_hva(hva)) { vcpu->arch.sta.shmem =3D INVALID_GPA; return; } --=20 2.34.1