bpf: Fix NULL-ptr-deref in btf_var_show()
Summary
| CVE | CVE-2026-98063 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-25 11:17:35 UTC |
| Updated | 2026-10-19 10:18:00 UTC |
| Description | 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: <TASK> 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) </TASK> Resolve the var's type directly with btf_type_skip_modifiers() when resolved_ids is NULL, mirroring btf_modifier_show(). |
Risk And Classification
EPSS: 0.001760000 probability, percentile 0.065280000 (date 2026-10-05)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected c4d0bfb45068d853a478b9067a95969b1886a30f 5756450c9a702da0efb4a993d0a6766b965736f3 git | Not specified |
| CNA | Linux | Linux | affected c4d0bfb45068d853a478b9067a95969b1886a30f e83fcbe3b5d4a1ffb0569bb7c280358065c6017a git | Not specified |
| CNA | Linux | Linux | affected c4d0bfb45068d853a478b9067a95969b1886a30f e0d6a06171633d3ee3f7a39b57e5c845fb2b79f2 git | Not specified |
| CNA | Linux | Linux | affected c4d0bfb45068d853a478b9067a95969b1886a30f aec0a9c1579eb9edf534960be592d09481bd7ac3 git | Not specified |
| CNA | Linux | Linux | affected c4d0bfb45068d853a478b9067a95969b1886a30f e472ae0d97865e2021ee668a13eab64013aebf23 git | Not specified |
| CNA | Linux | Linux | affected c4d0bfb45068d853a478b9067a95969b1886a30f ca086264e98108b44fdf53971033811a48defe2b git | Not specified |
| CNA | Linux | Linux | affected c4d0bfb45068d853a478b9067a95969b1886a30f ea383b3ea56979ce54c8aa88e6ec67164986c401 git | Not specified |
| CNA | Linux | Linux | affected c4d0bfb45068d853a478b9067a95969b1886a30f 5403a383f52fc0905703b488f7c3db4b2447dc58 git | Not specified |
| CNA | Linux | Linux | affected 5.10 | Not specified |
| CNA | Linux | Linux | unaffected 5.10 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.271 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.222 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.189 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.158 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.111 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.53 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.7 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/e83fcbe3b5d4a1ffb0569bb7c280358065c6017a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/aec0a9c1579eb9edf534960be592d09481bd7ac3 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/5403a383f52fc0905703b488f7c3db4b2447dc58 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/ea383b3ea56979ce54c8aa88e6ec67164986c401 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/e0d6a06171633d3ee3f7a39b57e5c845fb2b79f2 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/ca086264e98108b44fdf53971033811a48defe2b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/5756450c9a702da0efb4a993d0a6766b965736f3 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/e472ae0d97865e2021ee668a13eab64013aebf23 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.