{"id":"AZL-104391","summary":"CVE-2026-98064 affecting package kernel 6.6.157.1-1","details":"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)-\u003eshow() unconditionally. For the void type (type_id 0,\nBTF_KIND_UNKN) kind_ops[] has no entry, so -\u003eshow 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 \u003cTASK\u003e\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 \u003c/TASK\u003e\n\nFall back to btf_df_show() when the resolved type has no show op; it\nemits the \"\u003cunsupported kind:N\u003e\" placeholder already used for kinds like\nFWD and FUNC. bpf_snprintf_btf() then returns the length as usual.","modified":"2026-09-27T05:34:32Z","published":"2026-09-25T11:17:35Z","upstream":["CVE-2026-98064"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98064"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.157.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-104391.json"}}],"schema_version":"1.9.0"}