{"id":"CVE-2026-98064","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix NULL-ptr-deref when showing a void BTF type\n\nbtf_modifier_show() resolves the modifier and then calls\nbtf_type_ops(t)->show() unconditionally","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix NULL-ptr-deref when showing a void BTF type\n\nbtf_modifier_show() resolves the modifier and then calls\nbtf_type_ops(t)->show() unconditionally. For the void typ…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-476"],"vendor":"Linux","product":"Linux","affected":["Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < cf528f2d7a0a54f2a3c6d439cfa3c8d7dfe90d8d","Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < adb15557a641cb8a31f83e5f62bd12042b138c7b","Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < 62b00074b58ccf43f61f70f2cfcac80937b530c6","Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < 86d86f9fcf62dd3654090fbf3cf7ae5f42aa0706","Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < 717abdfd1d559d01fdd102023f0a990fb0437240","Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < 98f1cb95221332139acf514350ae2cae3b8656c5","Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < 5324f4e75ff6e9c2ca2e267c5f34f0937f9d0ac9","Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < 4ea508b9ebd78bce7f212166d2e2cba66b875f08","Linux 5.10"],"published":"2026-09-25","updated":"2026-10-03","sourceUpdated":"2026-10-03T11:18:27.030","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98064","references":[{"url":"https://git.kernel.org/stable/c/4ea508b9ebd78bce7f212166d2e2cba66b875f08","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5324f4e75ff6e9c2ca2e267c5f34f0937f9d0ac9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/62b00074b58ccf43f61f70f2cfcac80937b530c6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/717abdfd1d559d01fdd102023f0a990fb0437240","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/86d86f9fcf62dd3654090fbf3cf7ae5f42aa0706","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/98f1cb95221332139acf514350ae2cae3b8656c5","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/adb15557a641cb8a31f83e5f62bd12042b138c7b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cf528f2d7a0a54f2a3c6d439cfa3c8d7dfe90d8d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98064.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98064"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541283"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98064"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98064"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98064.mbox"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00177,"epssPercentile":0.07178,"cvssSource":"vendor","ingestedAt":"2026-09-25T11:06:38.841Z","slug":"CVE-2026-98064","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix NULL-ptr-deref when showing a void BTF type\n\nbtf_modifier_show() resolves the modifier and then calls\nbtf_type_ops(t)->show() unconditionally. For the void type (type_id 0,\nBTF_KIND_UNKN) kind_ops[] has no entry, so ->show is NULL.\n\nA \"const void\" (a modifier resolving to void) cannot be a map key or\nvalue - map_check_btf() rejects it because void has no size - so the map\ndump path does not reach it. But bpf_snprintf_btf() takes a type_id\nstraight from the BPF program, and passing such a \"const void\" from the\nvmlinux BTF NULL-derefs:\n\nKASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]\nRIP: 0010:btf_modifier_show (kernel/bpf/btf.c:2914)\nCall Trace:\n <TASK>\n btf_type_show (kernel/bpf/btf.c:8251)\n btf_type_snprintf_show (kernel/bpf/btf.c:8321)\n bpf_snprintf_btf (kernel/trace/bpf_trace.c:1047)\n bpf_prog_test_run_raw_tp (net/bpf/test_run.c:829)\n __sys_bpf (kernel/bpf/syscall.c:4804)\n do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n </TASK>\n\nFall back to btf_df_show() when the resolved type has no show op; it\nemits the \"<unsupported kind:N>\" placeholder already used for kinds like\nFWD and FUNC. bpf_snprintf_btf() then returns the length as usual.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98064.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":212371,"id":"CVE-2026-98064","ts":1790668159490,"field":"cvss","old":null,"new":"5.5"},{"seq":212370,"id":"CVE-2026-98064","ts":1790668159490,"field":"severity","old":"none","new":"medium"}]}