fkie_cve-2023-54247
Vulnerability from fkie_nvd
Published
2025-12-30 13:16
Modified
2025-12-31 20:42
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Silence a warning in btf_type_id_size() syzbot reported a warning in [1] with the following stacktrace: WARNING: CPU: 0 PID: 5005 at kernel/bpf/btf.c:1988 btf_type_id_size+0x2d9/0x9d0 kernel/bpf/btf.c:1988 ... RIP: 0010:btf_type_id_size+0x2d9/0x9d0 kernel/bpf/btf.c:1988 ... Call Trace: <TASK> map_check_btf kernel/bpf/syscall.c:1024 [inline] map_create+0x1157/0x1860 kernel/bpf/syscall.c:1198 __sys_bpf+0x127f/0x5420 kernel/bpf/syscall.c:5040 __do_sys_bpf kernel/bpf/syscall.c:5162 [inline] __se_sys_bpf kernel/bpf/syscall.c:5160 [inline] __x64_sys_bpf+0x79/0xc0 kernel/bpf/syscall.c:5160 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd With the following btf [1] DECL_TAG 'a' type_id=4 component_idx=-1 [2] PTR '(anon)' type_id=0 [3] TYPE_TAG 'a' type_id=2 [4] VAR 'a' type_id=3, linkage=static and when the bpf_attr.btf_key_type_id = 1 (DECL_TAG), the following WARN_ON_ONCE in btf_type_id_size() is triggered: if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) && !btf_type_is_var(size_type))) return NULL; Note that 'return NULL' is the correct behavior as we don't want a DECL_TAG type to be used as a btf_{key,value}_type_id even for the case like 'DECL_TAG -> STRUCT'. So there is no correctness issue here, we just want to silence warning. To silence the warning, I added DECL_TAG as one of kinds in btf_type_nosize() which will cause btf_type_id_size() returning NULL earlier without the warning. [1] https://lore.kernel.org/bpf/000000000000e0df8d05fc75ba86@google.com/
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/61f4bd46a03a81865aca3bcbad2f7b7032fb3160
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7c4f5ab63e7962812505cbd38cc765168a223acb
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e6c2f594ed961273479505b42040782820190305
Impacted products
Vendor Product Version


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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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 \u0027a\u0027 type_id=4 component_idx=-1\n  [2] PTR \u0027(anon)\u0027 type_id=0\n  [3] TYPE_TAG \u0027a\u0027 type_id=2\n  [4] VAR \u0027a\u0027 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) \u0026\u0026\n                   !btf_type_is_var(size_type)))\n          return NULL;\n\nNote that \u0027return NULL\u0027 is the correct behavior as we don\u0027t want\na DECL_TAG type to be used as a btf_{key,value}_type_id even\nfor the case like \u0027DECL_TAG -\u003e STRUCT\u0027. 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/"
    }
  ],
  "id": "CVE-2023-54247",
  "lastModified": "2025-12-31T20:42:43.210",
  "metrics": {},
  "published": "2025-12-30T13:16:13.327",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/61f4bd46a03a81865aca3bcbad2f7b7032fb3160"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7c4f5ab63e7962812505cbd38cc765168a223acb"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e6c2f594ed961273479505b42040782820190305"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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