{"id":"CVE-2026-98599","title":"bpf: Reject non-negative offsets in stack_slot_obj_get_spi()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject non-negative offsets in stack_slot_obj_get_spi()\n\nbpf_get_spi() computes (-off - 1) / BPF_REG_SIZE using C division,\nwhich truncates toward zero. For off ==…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 06accc8779c1d558a5b5a21f2ac82b0c95827ddd < 89a7241fc7ecc1b5e47c3f071081e314523b8d9d","Linux >= 06accc8779c1d558a5b5a21f2ac82b0c95827ddd < 79a9172f3ab4ad8392c5e5c8944b9b7710ade620","Linux 6.4"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:19:11.941Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98599","references":[{"url":"https://git.kernel.org/stable/c/89a7241fc7ecc1b5e47c3f071081e314523b8d9d"},{"url":"https://git.kernel.org/stable/c/79a9172f3ab4ad8392c5e5c8944b9b7710ade620"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T15:45:12.244Z","slug":"CVE-2026-98599","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject non-negative offsets in stack_slot_obj_get_spi()\n\nbpf_get_spi() computes (-off - 1) / BPF_REG_SIZE using C division,\nwhich truncates toward zero. For off == 0, this produces spi 0, the\nsame index used by the valid stack slot at fp-8.\n\nstack_slot_obj_get_spi() currently checks alignment and the resulting\nspi bounds, but does not reject the non-negative offset itself. It can\ntherefore validate a PTR_TO_STACK register holding fp+0 against an\niterator stored at fp-8 even though the runtime receives the actual fp+0\npointer. An effectful iterator kfunc can then interpret memory outside\nthe BPF stack as iterator state.\n\nReject non-negative offsets before converting the offset to an spi. All\nvalid stack objects begin at a negative offset from the frame pointer.\n\n## Affected\n\n- `Linux >= 06accc8779c1d558a5b5a21f2ac82b0c95827ddd < 89a7241fc7ecc1b5e47c3f071081e314523b8d9d`\n- `Linux >= 06accc8779c1d558a5b5a21f2ac82b0c95827ddd < 79a9172f3ab4ad8392c5e5c8944b9b7710ade620`\n- `Linux 6.4`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}