{"id":"CVE-2026-43274","state":"PUBLISHED","title":"mailbox: mchp-ipc-sbi: fix out-of-bounds access in mchp_ipc_get_cluster_aggr_irq()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmailbox: mchp-ipc-sbi: fix out-of-bounds access in mchp_ipc_get_cluster_aggr_irq()\n\nThe cluster_cfg array is dynamically allocated to hold per-CPU\nconfiguration structures, with its size based on the number of online\nCPUs. Previously, this array was indexed using hartid, which may be\nnon-contiguous or exceed the bounds of the array, leading to\nout-of-bounds access.\nSwitch to using cpuid as the index, as it is guaranteed to be within\nthe valid range provided by for_each_online_cpu().","publishedAt":"2026-05-06T11:28:57.503Z","updatedAt":"2026-08-05T12:26:59.090Z","severity":{"score":8.4,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e4b1d67e71419c4af581890ecea84b04920d4116","status":"affected","lessThan":"95438699c92947155823dcd3918049a07f3cd867","versionType":"git"},{"version":"e4b1d67e71419c4af581890ecea84b04920d4116","status":"affected","lessThan":"0442b6229e2eedc95a6d3d18ce75dec7f5b5377c","versionType":"git"},{"version":"e4b1d67e71419c4af581890ecea84b04920d4116","status":"affected","lessThan":"f7c330a8c83c9b0332fd524097eaf3e69148164d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/mailbox/mailbox-mchp-ipc-sbi.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.14","versionType":"semver"},{"version":"6.18.16","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.6","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/mailbox/mailbox-mchp-ipc-sbi.c"]}],"references":["https://git.kernel.org/stable/c/95438699c92947155823dcd3918049a07f3cd867","https://git.kernel.org/stable/c/0442b6229e2eedc95a6d3d18ce75dec7f5b5377c","https://git.kernel.org/stable/c/f7c330a8c83c9b0332fd524097eaf3e69148164d"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43274.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43274","state":"PUBLISHED","datePublished":"2026-05-06T11:28:57.503Z","dateUpdated":"2026-08-05T12:26:59.090Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:55.998Z"},"containers":{"cna":{"title":"mailbox: mchp-ipc-sbi: fix out-of-bounds access in mchp_ipc_get_cluster_aggr_irq()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmailbox: mchp-ipc-sbi: fix out-of-bounds access in mchp_ipc_get_cluster_aggr_irq()\n\nThe cluster_cfg array is dynamically allocated to hold per-CPU\nconfiguration structures, with its size based on the number of online\nCPUs. Previously, this array was indexed using hartid, which may be\nnon-contiguous or exceed the bounds of the array, leading to\nout-of-bounds access.\nSwitch to using cpuid as the index, as it is guaranteed to be within\nthe valid range provided by for_each_online_cpu()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e4b1d67e71419c4af581890ecea84b04920d4116","status":"affected","lessThan":"95438699c92947155823dcd3918049a07f3cd867","versionType":"git"},{"version":"e4b1d67e71419c4af581890ecea84b04920d4116","status":"affected","lessThan":"0442b6229e2eedc95a6d3d18ce75dec7f5b5377c","versionType":"git"},{"version":"e4b1d67e71419c4af581890ecea84b04920d4116","status":"affected","lessThan":"f7c330a8c83c9b0332fd524097eaf3e69148164d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/mailbox/mailbox-mchp-ipc-sbi.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.14","versionType":"semver"},{"version":"6.18.16","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.6","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/mailbox/mailbox-mchp-ipc-sbi.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/95438699c92947155823dcd3918049a07f3cd867"},{"url":"https://git.kernel.org/stable/c/0442b6229e2eedc95a6d3d18ce75dec7f5b5377c"},{"url":"https://git.kernel.org/stable/c/f7c330a8c83c9b0332fd524097eaf3e69148164d"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.4,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable code is reached through local platform-driver probe and the local Microchip IPC/IHC interrupt path, not through network packets. A plausible attacker would need local control of the affected platform/IPC peer or firmware configuration to trigger the bad hart/IRQ condition.\nAC:L - The bug is a direct non-contiguous hart ID versus CPU index mismatch with no race or timing requirement. Such hart mappings are plausible for this Microchip RISC-V platform, so triggering does not depend on conditions outside the attacker's control once the affected path is reachable.\nPR:N - The vulnerable probe and IRQ handler perform no Linux credential, capability, or authentication checks. An attacker able to drive the local IPC peer/firmware-triggered path does not need privileges inside the vulnerable Linux instance.\nUI:N - No victim action is required after the affected platform path is reachable. Probe-time setup or an IPC interrupt can hit the vulnerable access automatically.\nS:U - The corruption occurs in the Linux kernel driver and impacts the same kernel security authority. There is no VM escape, IOMMU bypass, or cross-authority boundary shown.\nC:H - The out-of-bounds index can read adjacent kernel memory/pointer fields and feed invalid buffer addresses into the SBI status path. Conservatively, this kernel OOB access can expose sensitive memory.\nI:H - The vulnerable probe path writes `irq`, `buf_base`, and `buf_base_addr` through an out-of-bounds `cluster_cfg[hartid]` index. This is kernel heap memory corruption and can plausibly be leveraged for control-flow or data integrity compromise.\nA:H - The same out-of-bounds access can corrupt kernel memory or dereference/copy through invalid pointers in interrupt context. A kernel oops, panic, or boot-time failure is a high availability impact."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:26:59.090Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.18.16"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.19.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}