Skip to main content
cve.nowby Sazabi
← All vulnerabilities
CVE-2026-98063

bpf: Fix NULL-ptr-deref in btf_var_show()

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, and 2 more
None on Exploit-DB, Metasploit or GitHub

Summary

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().

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Linux Linux

    From c4d0bfb45068d853a478b9067a95969b1886a30f · fixed in 5756450c9a702da0efb4a993d0a6766b965736f3; From c4d0bfb45068d853a478b9067a95969b1886a30f · fixed in e83fcbe3b5d4a1ffb0569bb7c280358065c6017a; From c4d0bfb45068d853a478b9067a95969b1886a30f · fixed in e0d6a06171633d3ee3f7a39b57e5c845fb2b79f2; From c4d0bfb45068d853a478b9067a95969b1886a30f · fixed in aec0a9c1579eb9edf534960be592d09481bd7ac3; From c4d0bfb45068d853a478b9067a95969b1886a30f · fixed in e472ae0d97865e2021ee668a13eab64013aebf23; From c4d0bfb45068d853a478b9067a95969b1886a30f · fixed in ca086264e98108b44fdf53971033811a48defe2b; From c4d0bfb45068d853a478b9067a95969b1886a30f · fixed in ea383b3ea56979ce54c8aa88e6ec67164986c401; From c4d0bfb45068d853a478b9067a95969b1886a30f · fixed in 5403a383f52fc0905703b488f7c3db4b2447dc58

  • Linux Linux

    5.10

  • KernelLinux

    From 5.10.0 · fixed in 5.10.271; From 5.11.0 · fixed in 5.15.222; From 5.16.0 · fixed in 6.1.189; From 6.2.0 · fixed in 6.6.158; From 6.7.0 · fixed in 6.12.111; From 6.13.0 · fixed in 6.18.53; From 6.19.0 · fixed in 7.2.7

References 8

git.kernel.org