{"id":"CVE-2026-99092","aliases":[],"title":"riscv: patch: fix handling of bpf-jit execmem addresses","titleSource":"Linux","descriptionSource":"Linux","products":[{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"2c9e5d4a008293407836d29d35dfd4353615bd2f","status":"affected","lessThan":"562a35b9e0b3d9483d9472995219cadb3592db3d","versionType":"git"},{"version":"2c9e5d4a008293407836d29d35dfd4353615bd2f","status":"affected","lessThan":"9e8fc7972b398e9dc2415ece283d8f64edac3858","versionType":"git"},{"version":"2c9e5d4a008293407836d29d35dfd4353615bd2f","status":"affected","lessThan":"f71d6ea3843c8038c431c2699482f246aea37ca0","versionType":"git"},{"version":"2c9e5d4a008293407836d29d35dfd4353615bd2f","status":"affected","lessThan":"a510e1ae8c9030750c2edf7b0bc9b186cd8c7a06","versionType":"git"}],"defaultStatus":"unaffected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99092"},{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"6.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.10","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.58","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.11","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"defaultStatus":"affected","source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-99092"}],"remediation":[],"description":"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().","severity":"unknown","score":null,"published":"2026-10-26T14:52:00.860Z","modified":"2026-10-26T14:52:00.860Z","withdrawn":false,"knownExploited":false,"affected":[],"references":["https://git.kernel.org/stable/c/562a35b9e0b3d9483d9472995219cadb3592db3d","https://git.kernel.org/stable/c/9e8fc7972b398e9dc2415ece283d8f64edac3858","https://git.kernel.org/stable/c/f71d6ea3843c8038c431c2699482f246aea37ca0","https://git.kernel.org/stable/c/a510e1ae8c9030750c2edf7b0bc9b186cd8c7a06"],"sources":[{"name":"CVE","id":"CVE-2026-99092","modified":"2026-10-26T14:52:00.860Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-99092"}],"assessments":[],"sourceAffected":[],"kev":{"status":"not-listed","checkedAt":"2026-10-29T02:15:32.063Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[]}