{"id":"CVE-2026-93045","summary":"bpf: Reject arena frees below the arena base","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject arena frees below the arena base\n\nbpf_arena_free_pages() accepts scalar arena addresses. The runtime\nmasks the address to the low 32 bits and reconstructs a full user\naddress from the arena base before returning the range to the arena\nfree tree.\n\nWhen the scalar value is below the low 32 bits of the arena base,\nfull_uaddr falls below user_vm_start. The existing upper-end clipping\nthen turns this into an out-of-range free-tree offset. A later\nallocation can reuse that offset and return an address below the arena\nmapping.\n\nReject such frees before computing the clipped range.","modified":"2026-09-20T11:30:53.127057951Z","published":"2026-09-17T16:10:36.988Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93045.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/8a08635656037aee9c12231ed384449c4ffb1a93"},{"type":"WEB","url":"https://git.kernel.org/stable/c/90453eaf8f14e7be0ab03983f2a93aeb6b990a58"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a968dffa5ab3c74d2ebb3a6233bf8b843f0bfc20"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b5a71cb2db6d84ac0042549dcec266b18429d41e"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93045.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93045"},{"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":"317460317a02a1af512697e6e964298dedd8a163"},{"fixed":"90453eaf8f14e7be0ab03983f2a93aeb6b990a58"},{"fixed":"a968dffa5ab3c74d2ebb3a6233bf8b843f0bfc20"},{"fixed":"8a08635656037aee9c12231ed384449c4ffb1a93"},{"fixed":"b5a71cb2db6d84ac0042549dcec266b18429d41e"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93045.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.9.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93045.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}