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(unknown [210.73.43.101]) by APP-05 (Coremail) with SMTP id zQCowAAXpglFhKppgcC9CQ--.1822S3; Fri, 06 Mar 2026 15:37:43 +0800 (CST) From: Jiakai Xu To: linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, kvm-riscv@lists.infradead.org, kvm@vger.kernel.org Cc: Andrew Jones , Alexandre Ghiti , Albert Ou , Palmer Dabbelt , Paul Walmsley , Atish Patra , Anup Patel , Jiakai Xu , Jiakai Xu Subject: [PATCH 1/2] RISC-V: KVM: Fix array out-of-bounds in pmu_ctr_read() Date: Fri, 6 Mar 2026 07:37:38 +0000 Message-Id: <20260306073739.3441292-2-xujiakai2025@iscas.ac.cn> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260306073739.3441292-1-xujiakai2025@iscas.ac.cn> References: <20260306073739.3441292-1-xujiakai2025@iscas.ac.cn> 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: zQCowAAXpglFhKppgcC9CQ--.1822S3 X-Coremail-Antispam: 1UD129KBjvJXoW7Cw43uw45GF1xXw43Ar1fJFb_yoW8Ar15pr sFkr9a93s5trs29w1Yyw1Duw4jyw4kGan8CrWDGF18Ar4a9r97JF1v93srJr1fAFZFqa4x ta1Fka4xCFW5Xa7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUQF14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jr4l82xGYIkIc2 x26xkF7I0E14v26r4j6ryUM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAa c4AC62xK8xCEY4vEwIxC4wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzV Aqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Gr0_Cr1lOx8S 6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxw ACI402YVCY1x02628vn2kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxG rwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4 vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IY x2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26c xKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAF wI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUn18PUUUUU= X-CM-SenderInfo: 50xmxthndljiysv6x2xfdvhtffof0/1tbiBgwSCWmqYdd74wAAs8 Content-Type: text/plain; charset="utf-8" When a guest invokes SBI_EXT_PMU_COUNTER_FW_READ on a firmware counter that has not been configured via SBI_EXT_PMU_COUNTER_CFG_MATCH, the pmc->event_idx remains SBI_PMU_EVENT_IDX_INVALID (0xFFFFFFFF). get_event_code() extracts the lower 16 bits, yielding 0xFFFF (65535), which is then used to index into kvpmu->fw_event[]. Since fw_event is only RISCV_KVM_MAX_FW_CTRS (32) entries, this triggers an array-index-out-of-bounds: UBSAN: array-index-out-of-bounds in arch/riscv/kvm/vcpu_pmu.c:255:37 index 65535 is out of range for type 'kvm_fw_event [32]' Add a bounds check on fevent_code before accessing the fw_event array, returning -EINVAL for invalid event codes. Fixes: badc386869e2c ("RISC-V: KVM: Support firmware events") Signed-off-by: Jiakai Xu Signed-off-by: Jiakai Xu --- arch/riscv/kvm/vcpu_pmu.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c index e873430e596b..c6d42459c2a1 100644 --- a/arch/riscv/kvm/vcpu_pmu.c +++ b/arch/riscv/kvm/vcpu_pmu.c @@ -252,6 +252,10 @@ static int pmu_ctr_read(struct kvm_vcpu *vcpu, unsigne= d long cidx, =20 if (pmc->cinfo.type =3D=3D SBI_PMU_CTR_TYPE_FW) { fevent_code =3D get_event_code(pmc->event_idx); + if (fevent_code >=3D SBI_PMU_FW_MAX) { + pr_warn("Invalid firmware event code [%d] for counter [%ld]\n", fevent_= code, cidx); + return -EINVAL; + } pmc->counter_val =3D kvpmu->fw_event[fevent_code].value; } else if (pmc->perf_event) { pmc->counter_val +=3D perf_event_read_value(pmc->perf_event, &enabled, &= running); --=20 2.34.1