{"schema":"threatline.record/2","record":{"id":"CVE-2026-99092","aliases":[],"summary":"riscv: patch: fix handling of bpf-jit execmem addresses","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nriscv: patch: fix handling of bpf-jit execmem addresses\n\nCommit 8718e5a3090b (\"riscv: patch: skip fixmap mapping when kernel text\nis already writable\") gated the core_kernel_text() branch of patch_map()\non CONFIG_STRICT_KERNEL_RWX, and explicitly left the vmalloc branch\nunchanged. That branch has a separate problem.\n\nThat branch only creates a temporary writable fixmap alias when\nCONFIG_STRICT_MODULE_RWX is enabled, and otherwise assumes the target is\ndirectly writable and returns the address unchanged. That assumption no\nlonger holds: bpf_prog_pack_alloc calls set_memory_rox() on every pack\nunconditionally in alloc_new_pack(), independently of any\nCONFIG_STRICT_*_RWX option, so BPF text in the vmalloc area is read-only\nregardless of what CONFIG_STRICT_MODULE_RWX says.\n\nWith CONFIG_STRICT_MODULE_RWX=n, patch_map() returns the read-only\naddress directly, the subsequent copy_to_kernel_nofault() takes a\npage fault and returns -EFAULT. bpf_arch_text_copy() turns that into\n-EINVAL, which propagates through bpf_jit_binary_pack_finalize() to the\nWARN_ON() in bpf_int_jit_compile() and leaves the program un-JITed.\n\nNote that BPF cannot be fixed the way kprobes was in\ncommit bdc46e507b59 (\"riscv: mm: make EXECMEM_KPROBES writable without\nCONFIG_STRICT_MODULE_RWX\"). EXECMEM_BPF is already PAGE_KERNEL, i.e.\nwritable at allocation time; the read-only mapping is established\nafterwards by generic code in alloc_new_pack(), which arch code cannot\ninfluence. The only place this can be handled is patch_map().\n\nThis is the same problem that was fixed on arm64 by commit b1480ed230ac\n(\"arm64: patching: fix handling of execmem addresses\"), and the fix is\nthe same: CONFIG_EXECMEM is what actually tracks whether the vmalloc\narea can hold executable memory that needs a temporary alias to be\nwritten. CONFIG_BPF_JIT, CONFIG_KPROBES and CONFIG_MODULES all select\nit.\n\nNote that this is not limited to CONFIG_MODULES=n. Unlike arm64, riscv\nselects CONFIG_ARCH_OPTIONAL_KERNEL_RWX, so CONFIG_STRICT_MODULE_RWX can\nbe disabled with CONFIG_MODULES=y as well, and the bug is reachable in\nthat configuration too.\n\nThe !CONFIG_MMU build is unaffected: it has its own __patch_insn_set()\nand __patch_insn_write() implementations and never calls patch_map().","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99092","source_modified_at":"2026-10-26T14:52:00.860Z","fetched_at":"2026-10-26T19:10:57.178988Z","product":"Linux","vendor":"Linux","versions":[{"version":"2c9e5d4a008293407836d29d35dfd4353615bd2f","lessThan":"562a35b9e0b3d9483d9472995219cadb3592db3d","status":"affected","versionType":"git"},{"version":"2c9e5d4a008293407836d29d35dfd4353615bd2f","lessThan":"9e8fc7972b398e9dc2415ece283d8f64edac3858","status":"affected","versionType":"git"},{"version":"2c9e5d4a008293407836d29d35dfd4353615bd2f","lessThan":"f71d6ea3843c8038c431c2699482f246aea37ca0","status":"affected","versionType":"git"},{"version":"2c9e5d4a008293407836d29d35dfd4353615bd2f","lessThan":"a510e1ae8c9030750c2edf7b0bc9b186cd8c7a06","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99092","source_modified_at":"2026-10-26T14:52:00.860Z","fetched_at":"2026-10-26T19:10:57.178988Z","product":"Linux","vendor":"Linux","versions":[{"version":"6.10","status":"affected"},{"version":"0","lessThan":"6.10","status":"unaffected","versionType":"semver"},{"version":"6.12.114","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.58","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.11","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99092","source_modified_at":"2026-10-26T14:52:00.860Z","fetched_at":"2026-10-26T19:10:57.178988Z","package":{"name":"Linux","ecosystem":null},"version":"562a35b9e0b3d9483d9472995219cadb3592db3d","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99092","source_modified_at":"2026-10-26T14:52:00.860Z","fetched_at":"2026-10-26T19:10:57.178988Z","package":{"name":"Linux","ecosystem":null},"version":"9e8fc7972b398e9dc2415ece283d8f64edac3858","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":null,"percentile":null,"score_date":null},"published_at":"2026-10-26T14:52:00.860Z","modified_at":"2026-10-26T14:52:00.860Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-99092","fetched_at":"2026-10-26T19:10:57.178988Z","source_modified_at":"2026-10-26T14:52:00.860Z"}],"sources":["CVE List"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/562a35b9e0b3d9483d9472995219cadb3592db3d"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/9e8fc7972b398e9dc2415ece283d8f64edac3858"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/f71d6ea3843c8038c431c2699482f246aea37ca0"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/a510e1ae8c9030750c2edf7b0bc9b186cd8c7a06"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-26T14:52:00.860Z","content_hash":"b68af24cf8afe553aede034b5507a12deb192c6b0200463b06e6ff5b6f9189dc"}}