bpf: Fix NULL-ptr-deref in btf_var_show()
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix NULL-ptr-deref in btf_var_show() btf_var_show() calls btf_type_id_resolve() unconditionally, which dereferences btf->resolved_ids. That is NULL for a base BTF - e.g. the vmlinux BTF that bpf_snprintf_btf() renders against - since base BTF is not resolved during parsing. btf_modifier_show() guards this with 'if (btf->resolved_ids)', but btf_var_show() does not. A BPF program that passes the type_id of a BTF_KIND_VAR from the vmlinux BTF to bpf_snprintf_btf() thus NULL-derefs: KASAN: probably user-memory-access in range [0x46638-0x4663f] RIP: 0010:btf_var_show (kernel/bpf/btf.c:2929) Call Trace: btf_type_show (kernel/bpf/btf.c:8259) btf_type_snprintf_show (kernel/bpf/btf.c:8329) 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:84) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Resolve the var's type directly with btf_type_skip_modifiers() when resolved_ids is NULL, mirroring btf_modifier_show().
CVE-2026-98063
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-98063
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "5756450c9a702da0efb4a993d0a6766b965736f3",
"versionType": "git"
},
{
"status": "affected",
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "e83fcbe3b5d4a1ffb0569bb7c280358065c6017a",
"versionType": "git"
},
{
"status": "affected",
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "e0d6a06171633d3ee3f7a39b57e5c845fb2b79f2",
"versionType": "git"
},
{
"status": "affected",
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "aec0a9c1579eb9edf534960be592d09481bd7ac3",
"versionType": "git"
},
{
"status": "affected",
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "e472ae0d97865e2021ee668a13eab64013aebf23",
"versionType": "git"
},
{
"status": "affected",
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "ca086264e98108b44fdf53971033811a48defe2b",
"versionType": "git"
},
{
"status": "affected",
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "ea383b3ea56979ce54c8aa88e6ec67164986c401",
"versionType": "git"
},
{
"status": "affected",
"version": "c4d0bfb45068d853a478b9067a95969b1886a30f",
"lessThan": "5403a383f52fc0905703b488f7c3db4b2447dc58",
"versionType": "git"
}
],
"programFiles": [
"kernel/bpf/btf.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.10"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.10",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.271",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.222",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"kernel/bpf/btf.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98063
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #38174 · Revision 1
- Added to Heist Feed
- Publisher date