{"id":"CVE-2023-54247","summary":"bpf: Silence a warning in btf_type_id_size()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Silence a warning in btf_type_id_size()\n\nsyzbot reported a warning in [1] with the following stacktrace:\n  WARNING: CPU: 0 PID: 5005 at kernel/bpf/btf.c:1988 btf_type_id_size+0x2d9/0x9d0 kernel/bpf/btf.c:1988\n  ...\n  RIP: 0010:btf_type_id_size+0x2d9/0x9d0 kernel/bpf/btf.c:1988\n  ...\n  Call Trace:\n   \u003cTASK\u003e\n   map_check_btf kernel/bpf/syscall.c:1024 [inline]\n   map_create+0x1157/0x1860 kernel/bpf/syscall.c:1198\n   __sys_bpf+0x127f/0x5420 kernel/bpf/syscall.c:5040\n   __do_sys_bpf kernel/bpf/syscall.c:5162 [inline]\n   __se_sys_bpf kernel/bpf/syscall.c:5160 [inline]\n   __x64_sys_bpf+0x79/0xc0 kernel/bpf/syscall.c:5160\n   do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n   do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80\n   entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nWith the following btf\n  [1] DECL_TAG 'a' type_id=4 component_idx=-1\n  [2] PTR '(anon)' type_id=0\n  [3] TYPE_TAG 'a' type_id=2\n  [4] VAR 'a' type_id=3, linkage=static\nand when the bpf_attr.btf_key_type_id = 1 (DECL_TAG),\nthe following WARN_ON_ONCE in btf_type_id_size() is triggered:\n  if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) &&\n                   !btf_type_is_var(size_type)))\n          return NULL;\n\nNote that 'return NULL' is the correct behavior as we don't want\na DECL_TAG type to be used as a btf_{key,value}_type_id even\nfor the case like 'DECL_TAG -\u003e STRUCT'. So there\nis no correctness issue here, we just want to silence warning.\n\nTo silence the warning, I added DECL_TAG as one of kinds in\nbtf_type_nosize() which will cause btf_type_id_size() returning\nNULL earlier without the warning.\n\n  [1] https://lore.kernel.org/bpf/000000000000e0df8d05fc75ba86@google.com/","modified":"2026-03-31T17:29:41.817327334Z","published":"2025-12-30T12:15:45.395Z","related":["SUSE-SU-2026:0278-1","SUSE-SU-2026:0281-1","SUSE-SU-2026:0293-1","SUSE-SU-2026:0315-1","SUSE-SU-2026:20477-1","SUSE-SU-2026:20498-1","SUSE-SU-2026:20845-1","SUSE-SU-2026:20876-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/54xxx/CVE-2023-54247.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/61f4bd46a03a81865aca3bcbad2f7b7032fb3160"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7c4f5ab63e7962812505cbd38cc765168a223acb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e6c2f594ed961273479505b42040782820190305"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/54xxx/CVE-2023-54247.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-54247"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b5ea834dde6b6e7f75e51d5f66dac8cd7c97b5ef"},{"fixed":"61f4bd46a03a81865aca3bcbad2f7b7032fb3160"},{"fixed":"7c4f5ab63e7962812505cbd38cc765168a223acb"},{"fixed":"e6c2f594ed961273479505b42040782820190305"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2023-54247.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.4.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2023-54247.json"}}],"schema_version":"1.7.5"}