{"id":"CVE-2026-98064","state":"PUBLISHED","title":"bpf: Fix NULL-ptr-deref when showing a void BTF type","description":"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 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.","publishedAt":"2026-09-25T10:24:07.811Z","updatedAt":"2026-10-19T09:13:14.000Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"cf528f2d7a0a54f2a3c6d439cfa3c8d7dfe90d8d","versionType":"git"},{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"adb15557a641cb8a31f83e5f62bd12042b138c7b","versionType":"git"},{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"62b00074b58ccf43f61f70f2cfcac80937b530c6","versionType":"git"},{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"86d86f9fcf62dd3654090fbf3cf7ae5f42aa0706","versionType":"git"},{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"717abdfd1d559d01fdd102023f0a990fb0437240","versionType":"git"},{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"98f1cb95221332139acf514350ae2cae3b8656c5","versionType":"git"},{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"5324f4e75ff6e9c2ca2e267c5f34f0937f9d0ac9","versionType":"git"},{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"4ea508b9ebd78bce7f212166d2e2cba66b875f08","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/btf.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.10","versionType":"semver"},{"version":"5.10.271","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/btf.c"]}],"references":["https://git.kernel.org/stable/c/cf528f2d7a0a54f2a3c6d439cfa3c8d7dfe90d8d","https://git.kernel.org/stable/c/adb15557a641cb8a31f83e5f62bd12042b138c7b","https://git.kernel.org/stable/c/62b00074b58ccf43f61f70f2cfcac80937b530c6","https://git.kernel.org/stable/c/86d86f9fcf62dd3654090fbf3cf7ae5f42aa0706","https://git.kernel.org/stable/c/717abdfd1d559d01fdd102023f0a990fb0437240","https://git.kernel.org/stable/c/98f1cb95221332139acf514350ae2cae3b8656c5","https://git.kernel.org/stable/c/5324f4e75ff6e9c2ca2e267c5f34f0937f9d0ac9","https://git.kernel.org/stable/c/4ea508b9ebd78bce7f212166d2e2cba66b875f08"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98064.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98064","state":"PUBLISHED","datePublished":"2026-09-25T10:24:07.811Z","dateUpdated":"2026-10-19T09:13:14.000Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:19:56.073Z"},"containers":{"cna":{"title":"bpf: Fix NULL-ptr-deref when showing a void BTF type","descriptions":[{"lang":"en","value":"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 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"cf528f2d7a0a54f2a3c6d439cfa3c8d7dfe90d8d","versionType":"git"},{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"adb15557a641cb8a31f83e5f62bd12042b138c7b","versionType":"git"},{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"62b00074b58ccf43f61f70f2cfcac80937b530c6","versionType":"git"},{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"86d86f9fcf62dd3654090fbf3cf7ae5f42aa0706","versionType":"git"},{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"717abdfd1d559d01fdd102023f0a990fb0437240","versionType":"git"},{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"98f1cb95221332139acf514350ae2cae3b8656c5","versionType":"git"},{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"5324f4e75ff6e9c2ca2e267c5f34f0937f9d0ac9","versionType":"git"},{"version":"c4d0bfb45068d853a478b9067a95969b1886a30f","status":"affected","lessThan":"4ea508b9ebd78bce7f212166d2e2cba66b875f08","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/btf.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.10","versionType":"semver"},{"version":"5.10.271","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.222","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.189","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/btf.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/cf528f2d7a0a54f2a3c6d439cfa3c8d7dfe90d8d"},{"url":"https://git.kernel.org/stable/c/adb15557a641cb8a31f83e5f62bd12042b138c7b"},{"url":"https://git.kernel.org/stable/c/62b00074b58ccf43f61f70f2cfcac80937b530c6"},{"url":"https://git.kernel.org/stable/c/86d86f9fcf62dd3654090fbf3cf7ae5f42aa0706"},{"url":"https://git.kernel.org/stable/c/717abdfd1d559d01fdd102023f0a990fb0437240"},{"url":"https://git.kernel.org/stable/c/98f1cb95221332139acf514350ae2cae3b8656c5"},{"url":"https://git.kernel.org/stable/c/5324f4e75ff6e9c2ca2e267c5f34f0937f9d0ac9"},{"url":"https://git.kernel.org/stable/c/4ea508b9ebd78bce7f212166d2e2cba66b875f08"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:13:14.000Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"5.10.271"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"5.15.222"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.1.189"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.12.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"7.2.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}