{"api_version":"1","generated_at":"2026-09-18T04:51:40+00:00","cve":"CVE-2026-89906","urls":{"html":"https://cve.report/CVE-2026-89906","api":"https://cve.report/api/cve/CVE-2026-89906.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89906","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89906"},"summary":{"title":"LoongArch: BPF: Refactor jump offset calculation in tail call","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: BPF: Refactor jump offset calculation in tail call\n\nThe old macro-based jmp_offset calculation derives the jump distance\nfrom a stale prior-pass code stride, which can lead to wrong branch\noffsets and soft lockups under extra JIT passes.\n\nFix this by calculating the offset directly on the absolute target:\n\"ctx->offset[insn + 1] - ctx->idx\".\n\nTo avoid a false 16-bit range check abort during size estimation, add\na \"ctx->image == NULL\" guard to inject a safe dummy offset.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-16 11:16:59","updated_at":"2026-09-16 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Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89906","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cd39d9e6b7e4c58fa77783e7aedf7ada51d02ea3 882b8912b7e92341fdb115ba0e2e5142a28684ff git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cd39d9e6b7e4c58fa77783e7aedf7ada51d02ea3 96f44d493c280ea161569c43d7ed0f3b0815803a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cd39d9e6b7e4c58fa77783e7aedf7ada51d02ea3 37d545d12f21c4d50612ecaebd7ae1e5bf91b2d8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1a782fa32e644aa9fbae6c8488f3e61221ac96e1 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 17c010fe45def335fe03a0718935416b04c7f349 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original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["arch/loongarch/net/bpf_jit.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"882b8912b7e92341fdb115ba0e2e5142a28684ff","status":"affected","version":"cd39d9e6b7e4c58fa77783e7aedf7ada51d02ea3","versionType":"git"},{"lessThan":"96f44d493c280ea161569c43d7ed0f3b0815803a","status":"affected","version":"cd39d9e6b7e4c58fa77783e7aedf7ada51d02ea3","versionType":"git"},{"lessThan":"37d545d12f21c4d50612ecaebd7ae1e5bf91b2d8","status":"affected","version":"cd39d9e6b7e4c58fa77783e7aedf7ada51d02ea3","versionType":"git"},{"status":"affected","version":"1a782fa32e644aa9fbae6c8488f3e61221ac96e1","versionType":"git"},{"status":"affected","version":"17c010fe45def335fe03a0718935416b04c7f349","versionType":"git"},{"status":"affected","version":"f83d469e16bb1f75991ca67c56786fb2aaa42bea","versionType":"git"},{"status":"affected","version":"f2b5e50cc04d7a049b385bc1c93b9cbf5f10c94f","versionType":"git"},{"status":"affected","version":"9262e3e04621558e875eb5afb5e726b648cd5949","versionType":"git"},{"lessThan":"6.2","status":"affected","version":"6.1.149","versionType":"semver"},{"lessThan":"6.7","status":"affected","version":"6.6.103","versionType":"semver"},{"lessThan":"6.13","status":"affected","version":"6.12.43","versionType":"semver"},{"lessThan":"6.16","status":"affected","version":"6.15.11","versionType":"semver"},{"lessThan":"6.17","status":"affected","version":"6.16.2","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["arch/loongarch/net/bpf_jit.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.17"},{"lessThan":"6.17","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.51","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.51","versionStartIncluding":"6.17","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.5","versionStartIncluding":"6.17","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"6.17","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.149","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.103","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.43","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16.2","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: BPF: Refactor jump offset calculation in tail call\n\nThe old macro-based jmp_offset calculation derives the jump distance\nfrom a stale prior-pass code stride, which can lead to wrong branch\noffsets and soft lockups under extra JIT passes.\n\nFix this by calculating the offset directly on the absolute target:\n\"ctx->offset[insn + 1] - ctx->idx\".\n\nTo avoid a false 16-bit range check abort during size estimation, add\na \"ctx->image == NULL\" guard to inject a safe dummy offset."}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - The bug is in the LoongArch eBPF JIT emit_bpf_tail_call() and is reached only by loading a program that uses bpf_tail_call via bpf(BPF_PROG_LOAD) on the local host. Kernel CNA guidance classifies BPF as a local attack vector.\nAC:L - The attacker fully controls the BPF bytecode, including bpf2bpf subprograms that force the extra JIT pass where the stale prior-pass stride is used. Wrong jmp_offset encodings are deterministic for a given program (the in-tree tailcall_bpf2bpf_1 case), with no race or layout outside attacker control.\nPR:L - BPF_MAP_TYPE_PROG_ARRAY is an unprivileged map type, bpf_tail_call_proto is returned before the CAP_BPF gate, and SOCKET_FILTER programs load without CAP_BPF where unprivileged BPF is enabled. Otherwise only CAP_BPF or a delegated BPF token in a user namespace is required, not init-namespace root.\nUI:N - The attacker loads the crafted program, attaches it to a socket they own or runs it with BPF_PROG_TEST_RUN, and triggers the miscompiled tail call themselves. No separate victim action is required.\nS:U - The wrong branches execute inside the host kernel's own JIT image and corrupt in-kernel control flow. That is standard kernel privilege-escalation impact, not a VM, IOMMU, or hypervisor boundary crossing.\nC:H - Miscomputed tail-call \"goto out\" branches can land inside the remaining sequence after the max_entries check, so an out-of-range index performs an OOB load of array->ptrs[] and treats the result as a function pointer, disclosing kernel memory. Mid-image jumps likewise execute attacker-shaped JIT loads at kernel privilege.\nI:H - The same OOB ptrs[] load is followed by an indirect jump through prog->bpf_func, hijacking kernel control flow. Branches that skip the NULL or tail-call-count checks, or that land mid-instruction, likewise yield a kernel-mode write and control-flow primitive.\nA:H - The fix and the prior incomplete tail-call offset patch document watchdog soft lockups from wrong, including backward, branches looping in kernel context. Any such hang, oops, or panic is Availability High."}]}],"providerMetadata":{"dateUpdated":"2026-09-16T14:39:55.665Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/882b8912b7e92341fdb115ba0e2e5142a28684ff"},{"url":"https://git.kernel.org/stable/c/96f44d493c280ea161569c43d7ed0f3b0815803a"},{"url":"https://git.kernel.org/stable/c/37d545d12f21c4d50612ecaebd7ae1e5bf91b2d8"}],"title":"LoongArch: BPF: Refactor jump offset calculation in tail call","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89906","datePublished":"2026-09-16T10:32:05.157Z","dateReserved":"2026-09-11T19:38:34.774Z","dateUpdated":"2026-09-16T14:39:55.665Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-16 11:16:59","lastModifiedDate":"2026-09-16 15:18:16","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89906","Ordinal":"1","Title":"LoongArch: BPF: Refactor jump offset calculation in tail call","CVE":"CVE-2026-89906","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89906","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: BPF: Refactor jump offset calculation in tail call\n\nThe old macro-based jmp_offset calculation derives the jump distance\nfrom a stale prior-pass code stride, which can lead to wrong branch\noffsets and soft lockups under extra JIT passes.\n\nFix this by calculating the offset directly on the absolute target:\n\"ctx->offset[insn + 1] - ctx->idx\".\n\nTo avoid a false 16-bit range check abort during size estimation, add\na \"ctx->image == NULL\" guard to inject a safe dummy offset.","Type":"Description","Title":"LoongArch: BPF: Refactor jump offset calculation in tail call"}]}}}