From nobody Sat Jun 13 06:22:12 2026 Received: from cstnet.cn (smtp25.cstnet.cn [159.226.251.25]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 86058221F39; Sat, 9 May 2026 11:41:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.25 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778326910; cv=none; b=WxauHODNZvkEhCffgWerKpxPkYQSB6LWjRSxB9kuH8+r8o1JPB+q3XE14UGN1ZA7pNN7iPqWJHjikLaltfMQjQSRC5/2U3hatgRRiEQISVUnwkvNTSbEAWFJsivJXzcV+5A/+a+Pl+jUxOWmYI/9Jm7fwhpOJJjrEQzMkUJUg0I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778326910; c=relaxed/simple; bh=bTGWTu+W0+QZJwn0RSSvWnQ6KJKxtjXeqkOZFxyYq3g=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=usLqZOitf4dOzbiIfMeFUFucv1tZ8mGQdWs5yb5QK2zYC6kNkhiVbUqkClPguCpEB3+OrMuPMLQnx0t8Dt0nHVPv3Dfg8Qj64MhO98qNBImdKQEfIAfmxNMIriuF6DyhjG6lJrlkLW0nWjWKX7j1mIMVChH/gwyC4Y4pd83LBVQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn; spf=pass smtp.mailfrom=iscas.ac.cn; arc=none smtp.client-ip=159.226.251.25 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iscas.ac.cn Received: from yzs (unknown [115.199.218.204]) by APP-05 (Coremail) with SMTP id zQCowAAHlQhjHf9pbOLKDw--.3401S2; Sat, 09 May 2026 19:41:24 +0800 (CST) From: Zishun Yi To: Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou Cc: Atish Patra , Alexandre Ghiti , Andrew Jones , kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Zishun Yi Subject: [PATCH] riscv: KVM: Fix missing TLB flush on HENVCFG.PMM updates Date: Sat, 9 May 2026 19:41:22 +0800 Message-ID: <20260509114122.1868327-1-vulab@iscas.ac.cn> X-Mailer: git-send-email 2.51.2 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: zQCowAAHlQhjHf9pbOLKDw--.3401S2 X-Coremail-Antispam: 1UD129KBjvJXoW7KrWrJF4fXF43CrWktr17GFg_yoW8Ar4UpF W3uF95uaykJF1xGF9rta12gF4jkr4vgasIgr9rA342vrZFyF1Fq3yvg34IyryUC3y8X3yF kr4YqFW5urn0v3JanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9j14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r4j6ryUM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s 0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xII jxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr 1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4IIrI8v6xkF7I0E8cxa n2IY04v7MxkF7I0En4kS14v26r1q6r43MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4 AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE 17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMI IF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4l IxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvf C2KfnxnUUI43ZEXa7VUbGQ6JUUUUU== X-CM-SenderInfo: pyxotu46lvutnvoduhdfq/1tbiCRACA2n+2gnStgAAs4 Content-Type: text/plain; charset="utf-8" According to the RISC-V Privileged ISA specification, if henvcfg.PMM is changed from or to a value where (XLEN-PMLEN) is less than the GPA width supported by the hgatp translation mode of that guest, hypervisors must execute an HFENCE.GVMA with rs1=3Dx0. Currently, when a guest dynamically changes pointer masking mode via the SBI FWFT extension, kvm_sbi_fwft_set_pointer_masking_pmlen() directly modifies the hardware CSR_HENVCFG from the non-one-reg-access path without issuing the required TLB invalidation Fix this by adding an unconditional HFENCE.GVMA after the CSR write. This vulnerability was discovered and reported by my SpecHunter, an AI-driven architecture specification analysis tool. Link: https://github.com/yizishun/rv-isa-sec/blob/master/output/riscv-isa-m= anual/pr-2494/linux.txt Fixes: 48d67106f4a7 ("RISC-V: KVM: Implement ONE_REG interface for SBI FWFT= state") Assisted-by: DeepSeek:DeepSeek-V4-Pro Signed-off-by: Zishun Yi --- arch/riscv/kvm/vcpu_sbi_fwft.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/riscv/kvm/vcpu_sbi_fwft.c b/arch/riscv/kvm/vcpu_sbi_fwft.c index 2eab15339694..c2bd3ae699fd 100644 --- a/arch/riscv/kvm/vcpu_sbi_fwft.c +++ b/arch/riscv/kvm/vcpu_sbi_fwft.c @@ -186,8 +186,10 @@ static long kvm_sbi_fwft_set_pointer_masking_pmlen(str= uct kvm_vcpu *vcpu, * update here so that VCPU see's pointer masking mode change * immediately. */ - if (!one_reg_access) + if (!one_reg_access) { csr_write(CSR_HENVCFG, vcpu->arch.cfg.henvcfg); + kvm_riscv_local_hfence_gvma_all(); + } =20 return SBI_SUCCESS; } --=20 2.51.2