{"id":"CVE-2026-53036","summary":"bpf, arm64: Fix off-by-one in check_imm signed range check","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, arm64: Fix off-by-one in check_imm signed range check\n\ncheck_imm(bits, imm) is used in the arm64 BPF JIT to verify that\na branch displacement (in arm64 instruction units) fits into the\nsigned N-bit immediate field of a B, B.cond or CBZ/CBNZ encoding\nbefore it is handed to the encoder. The macro currently tests for\n(imm \u003e 0 && imm \u003e\u003e bits) || (imm \u003c 0 && ~imm \u003e\u003e bits) which admits\nvalues in [-2^N, 2^N) — effectively a signed (N+1)-bit range. A\nsigned N-bit field only holds [-2^(N-1), 2^(N-1)), so the check\nadmits one extra bit of range on each side.\n\nIn particular, for check_imm19(), values in [2^18, 2^19) slip past\nthe check but do not fit into the 19-bit signed imm19 field of\nB.cond. aarch64_insn_encode_immediate() then masks the raw value\ninto the 19-bit field, setting bit 18 (the sign bit) and flipping\na forward branch into a backward one. Same class of issue exists\nfor check_imm26() and the B/BL encoding. Shift by (bits - 1)\ninstead of bits so the actual signed N-bit range is enforced.","modified":"2026-07-22T18:22:26.398016823Z","published":"2026-06-24T16:29:43.449Z","related":["SUSE-SU-2026:3130-1","SUSE-SU-2026:3166-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53036.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1a113b5497297871699cd498b1b83542e0db7f15"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1dd8be4ec722ce54e4cace59f3a4ba658111b3ec"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6927f0d6794aa73318bbfa929f1ff6065b0620df"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7fd3b41260c6120e7b60164afea5d961af6224f9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a5dfeb3b61065039488342d43ae06d4729d955d4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fb74defa1cca1a73177c0c761e641332e4f979a3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53036.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53036"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"e54bcde3d69d40023ae77727213d14f920eb264a"},{"fixed":"a5dfeb3b61065039488342d43ae06d4729d955d4"},{"fixed":"7fd3b41260c6120e7b60164afea5d961af6224f9"},{"fixed":"6927f0d6794aa73318bbfa929f1ff6065b0620df"},{"fixed":"1a113b5497297871699cd498b1b83542e0db7f15"},{"fixed":"fb74defa1cca1a73177c0c761e641332e4f979a3"},{"fixed":"1dd8be4ec722ce54e4cace59f3a4ba658111b3ec"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-53036.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.18.0"},{"fixed":"6.1.175"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.141"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.91"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.33"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-53036.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}