{"id":"CVE-2026-98064","published":"2026-09-25T11:17:35.437","lastModified":"2026-09-25T11:17:35.437","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.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/4ea508b9ebd78bce7f212166d2e2cba66b875f08","tags":[]},{"url":"https://git.kernel.org/stable/c/5324f4e75ff6e9c2ca2e267c5f34f0937f9d0ac9","tags":[]},{"url":"https://git.kernel.org/stable/c/717abdfd1d559d01fdd102023f0a990fb0437240","tags":[]},{"url":"https://git.kernel.org/stable/c/98f1cb95221332139acf514350ae2cae3b8656c5","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}