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(unknown [210.73.43.101]) by APP-03 (Coremail) with SMTP id rQCowAC30Ndvsq9p08A4Cg--.55585S3; Tue, 10 Mar 2026 13:56:00 +0800 (CST) From: Jiakai Xu To: kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-riscv@lists.infradead.org Cc: Albert Ou , Alexandre Ghiti , Andrew Jones , Anup Patel , Atish Patra , Palmer Dabbelt , Paolo Bonzini , Paul Walmsley , Shuah Khan , Jiakai Xu , Jiakai Xu Subject: [PATCH v3 1/2] RISC-V: KVM: Fix array out-of-bounds in pmu_ctr_read() and pmu_fw_ctr_read_hi() Date: Tue, 10 Mar 2026 05:55:56 +0000 Message-Id: <20260310055557.835531-2-xujiakai2025@iscas.ac.cn> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260310055557.835531-1-xujiakai2025@iscas.ac.cn> References: <20260310055557.835531-1-xujiakai2025@iscas.ac.cn> MIME-Version: 1.0 X-CM-TRANSID: rQCowAC30Ndvsq9p08A4Cg--.55585S3 X-Coremail-Antispam: 1UD129KBjvJXoWxCF1fCFW8Xw1rtF4kZw13Arb_yoW5Xw1fpr 47Kwn0q395trZ2vw1Yyw1Duw4Uta1kK398WrW7WF18Aw13Wry3JFyDW3sIqF43AF4Fqa4x tw1Ig3WxCFy5Xa7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUHj14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jr4l82xGYIkIc2 x26xkF7I0E14v26r4j6ryUM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAa c4AC62xK8xCEY4vEwIxC4wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzV Aqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUXVWUAwAv7VC2z280aVAFwI0_Gr0_Cr1lOx8S 6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxw ACI402YVCY1x02628vn2kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCY02Avz4vE14v_GrWl 42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJV WUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MIIYrxkI7VAK I48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F 4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY 6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfUj0edDUUUU X-Originating-IP: [210.73.43.101] X-CM-SenderInfo: 50xmxthndljiysv6x2xfdvhtffof0/1tbiBwkCCWmvo+0qZgAAsB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260309_225643_121020_F109FD6B X-CRM114-Status: GOOD ( 10.23 ) X-Spam-Score: -2.1 (--) X-Spam-Report: Spam detection software, running on the system "bombadil.infradead.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: When a guest invokes SBI_EXT_PMU_COUNTER_FW_READ or SBI_EXT_PMU_COUNTER_FW_READ_HI on a firmware counter that has not been configured via SBI_EXT_PMU_COUNTER_CFG_MATCH, the pmc->event_idx remains SBI_ [...] Content analysis details: (-2.1 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [159.226.251.81 listed in list.dnswl.org] 0.4 RCVD_IN_VALIDITY_CERTIFIED_BLOCKED RBL: ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. [159.226.251.81 listed in sa-trusted.bondedsender.org] 0.9 RCVD_IN_VALIDITY_SAFE_BLOCKED RBL: ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. [159.226.251.81 listed in sa-accredit.habeas.com] 0.8 RCVD_IN_VALIDITY_RPBL_BLOCKED RBL: ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. [159.226.251.81 listed in bl.score.senderscore.com] -0.0 SPF_PASS SPF: sender matches SPF record -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] X-BeenThere: kvm-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kvm-riscv" Errors-To: kvm-riscv-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org When a guest invokes SBI_EXT_PMU_COUNTER_FW_READ or SBI_EXT_PMU_COUNTER_FW_READ_HI 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 check for the known unconfigured case (SBI_PMU_EVENT_IDX_INVALID) and a WARN_ONCE guard for any unexpected out-of-bounds event codes, returning -EINVAL in both cases. Fixes: badc386869e2c ("RISC-V: KVM: Support firmware events") Fixes: 08fb07d6dcf71 ("RISC-V: KVM: Support 64 bit firmware counters on RV32") Signed-off-by: Jiakai Xu Signed-off-by: Jiakai Xu Reviewed-by: Andrew Jones --- V2 -> V3: - Added check for SBI_PMU_EVENT_IDX_INVALID. - Added WARN_ONCE for unexpected out-of-bounds event codes. V1 -> V2: - Merged the fixes for pmu_ctr_read() and pmu_fw_ctr_read_hi() into a single commit. - Removed the pr_warn, simply returning -EINVAL instead. --- arch/riscv/kvm/vcpu_pmu.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c index e873430e596b..c87a7b0037cf 100644 --- a/arch/riscv/kvm/vcpu_pmu.c +++ b/arch/riscv/kvm/vcpu_pmu.c @@ -226,7 +226,14 @@ static int pmu_fw_ctr_read_hi(struct kvm_vcpu *vcpu, unsigned long cidx, if (pmc->cinfo.type != SBI_PMU_CTR_TYPE_FW) return -EINVAL; + if (pmc->event_idx == SBI_PMU_EVENT_IDX_INVALID) + return -EINVAL; + fevent_code = get_event_code(pmc->event_idx); + if (WARN_ONCE(fevent_code >= SBI_PMU_FW_MAX, + "Invalid firmware event code: %d\n", fevent_code)) + return -EINVAL; + pmc->counter_val = kvpmu->fw_event[fevent_code].value; *out_val = pmc->counter_val >> 32; @@ -251,7 +258,14 @@ static int pmu_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx, pmc = &kvpmu->pmc[cidx]; if (pmc->cinfo.type == SBI_PMU_CTR_TYPE_FW) { + if (pmc->event_idx == SBI_PMU_EVENT_IDX_INVALID) + return -EINVAL; + fevent_code = get_event_code(pmc->event_idx); + if (WARN_ONCE(fevent_code >= SBI_PMU_FW_MAX, + "Invalid firmware event code: %d\n", fevent_code)) + return -EINVAL; + pmc->counter_val = kvpmu->fw_event[fevent_code].value; } else if (pmc->perf_event) { pmc->counter_val += perf_event_read_value(pmc->perf_event, &enabled, &running);