CVE-2026-98064
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix NULL-ptr-deref when showing a void BTF type btf_modifier_show() resolves the modifier and then calls btf_type_ops(t)->show() unconditionally. For the void type (type_id 0, BTF_KIND_UNKN) kind_ops[] has no entry, so ->show is NULL. A "const void" (a modifier resolving to void) cannot be a map key or value - map_check_btf() rejects it because void has no size - so the map dump path does not reach it. But bpf_snprintf_btf() takes a type_id straight from the BPF program, and passing such a "const void" from the vmlinux BTF NULL-derefs: KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] RIP: 0010:btf_modifier_show (kernel/bpf/btf.c:2914) Call Trace: <TASK> btf_type_show (kernel/bpf/btf.c:8251) btf_type_snprintf_show (kernel/bpf/btf.c:8321) bpf_snprintf_btf (kernel/trace/bpf_trace.c:1047) bpf_prog_test_run_raw_tp (net/bpf/test_run.c:829) __sys_bpf (kernel/bpf/syscall.c:4804) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) </TASK> Fall back to btf_df_show() when the resolved type has no show op; it emits the "<unsupported kind:N>" placeholder already used for kinds like FWD and FUNC. bpf_snprintf_btf() then returns the length as usual.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Undergoing Analysis
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-25 11:17:35.437000
Last modified
2026-10-19 10:18:00.973000
View original CVE JSON
{
"id": "CVE-2026-98064",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-25T11:17:35.437",
"lastModified": "2026-10-19T10:18:00.973",
"vulnStatus": "Undergoing Analysis",
"cveTags": [],
"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": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"kernel/bpf/btf.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "cf528f2d7a0a54f2a3c6d439cfa3c8d7dfe90d8d",
"versionType": "git",
"status": "affected"
},
{
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "adb15557a641cb8a31f83e5f62bd12042b138c7b",
"versionType": "git",
"status": "affected"
},
{
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "62b00074b58ccf43f61f70f2cfcac80937b530c6",
"versionType": "git",
"status": "affected"
},
{
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "86d86f9fcf62dd3654090fbf3cf7ae5f42aa0706",
"versionType": "git",
"status": "affected"
},
{
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "717abdfd1d559d01fdd102023f0a990fb0437240",
"versionType": "git",
"status": "affected"
},
{
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "98f1cb95221332139acf514350ae2cae3b8656c5",
"versionType": "git",
"status": "affected"
},
{
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "5324f4e75ff6e9c2ca2e267c5f34f0937f9d0ac9",
"versionType": "git",
"status": "affected"
},
{
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "4ea508b9ebd78bce7f212166d2e2cba66b875f08",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"kernel/bpf/btf.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5.10",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.10",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.271",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.222",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.189",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.158",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.111",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.53",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.7",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/4ea508b9ebd78bce7f212166d2e2cba66b875f08",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/5324f4e75ff6e9c2ca2e267c5f34f0937f9d0ac9",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/62b00074b58ccf43f61f70f2cfcac80937b530c6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/717abdfd1d559d01fdd102023f0a990fb0437240",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/86d86f9fcf62dd3654090fbf3cf7ae5f42aa0706",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/98f1cb95221332139acf514350ae2cae3b8656c5",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/adb15557a641cb8a31f83e5f62bd12042b138c7b",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/cf528f2d7a0a54f2a3c6d439cfa3c8d7dfe90d8d",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}