ghsa-xx7j-2fqw-vv47
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix a btf decl_tag bug when tagging a function
syzbot reported a btf decl_tag bug with stack trace below:
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 3592 Comm: syz-executor914 Not tainted 5.16.0-syzkaller-11424-gb7892f7d5cb2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:btf_type_vlen include/linux/btf.h:231 [inline] RIP: 0010:btf_decl_tag_resolve+0x83e/0xaa0 kernel/bpf/btf.c:3910 ... Call Trace: btf_resolve+0x251/0x1020 kernel/bpf/btf.c:4198 btf_check_all_types kernel/bpf/btf.c:4239 [inline] btf_parse_type_sec kernel/bpf/btf.c:4280 [inline] btf_parse kernel/bpf/btf.c:4513 [inline] btf_new_fd+0x19fe/0x2370 kernel/bpf/btf.c:6047 bpf_btf_load kernel/bpf/syscall.c:4039 [inline] __sys_bpf+0x1cbb/0x5970 kernel/bpf/syscall.c:4679 __do_sys_bpf kernel/bpf/syscall.c:4738 [inline] __se_sys_bpf kernel/bpf/syscall.c:4736 [inline] __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4736 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae
The kasan error is triggered with an illegal BTF like below: type 0: void type 1: int type 2: decl_tag to func type 3 type 3: func to func_proto type 8 The total number of types is 4 and the type 3 is illegal since its func_proto type is out of range.
Currently, the target type of decl_tag can be struct/union, var or func. Both struct/union and var implemented their own 'resolve' callback functions and hence handled properly in kernel. But func type doesn't have 'resolve' callback function. When btf_decl_tag_resolve() tries to check func type, it tries to get vlen of its func_proto type, which triggered the above kasan error.
To fix the issue, btf_decl_tag_resolve() needs to do btf_func_check() before trying to accessing func_proto type. In the current implementation, func type is checked with btf_func_check() in the main checking function btf_check_all_types(). To fix the above kasan issue, let us implement 'resolve' callback func type properly. The 'resolve' callback will be also called in btf_check_all_types() for func types.
{
"affected": [],
"aliases": [
"CVE-2022-49228"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-02-26T07:00:59Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix a btf decl_tag bug when tagging a function\n\nsyzbot reported a btf decl_tag bug with stack trace below:\n\n general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN\n KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\n CPU: 0 PID: 3592 Comm: syz-executor914 Not tainted 5.16.0-syzkaller-11424-gb7892f7d5cb2 #0\n Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\n RIP: 0010:btf_type_vlen include/linux/btf.h:231 [inline]\n RIP: 0010:btf_decl_tag_resolve+0x83e/0xaa0 kernel/bpf/btf.c:3910\n ...\n Call Trace:\n \u003cTASK\u003e\n btf_resolve+0x251/0x1020 kernel/bpf/btf.c:4198\n btf_check_all_types kernel/bpf/btf.c:4239 [inline]\n btf_parse_type_sec kernel/bpf/btf.c:4280 [inline]\n btf_parse kernel/bpf/btf.c:4513 [inline]\n btf_new_fd+0x19fe/0x2370 kernel/bpf/btf.c:6047\n bpf_btf_load kernel/bpf/syscall.c:4039 [inline]\n __sys_bpf+0x1cbb/0x5970 kernel/bpf/syscall.c:4679\n __do_sys_bpf kernel/bpf/syscall.c:4738 [inline]\n __se_sys_bpf kernel/bpf/syscall.c:4736 [inline]\n __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4736\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x44/0xae\n\nThe kasan error is triggered with an illegal BTF like below:\n type 0: void\n type 1: int\n type 2: decl_tag to func type 3\n type 3: func to func_proto type 8\nThe total number of types is 4 and the type 3 is illegal\nsince its func_proto type is out of range.\n\nCurrently, the target type of decl_tag can be struct/union, var or func.\nBoth struct/union and var implemented their own \u0027resolve\u0027 callback functions\nand hence handled properly in kernel.\nBut func type doesn\u0027t have \u0027resolve\u0027 callback function. When\nbtf_decl_tag_resolve() tries to check func type, it tries to get\nvlen of its func_proto type, which triggered the above kasan error.\n\nTo fix the issue, btf_decl_tag_resolve() needs to do btf_func_check()\nbefore trying to accessing func_proto type.\nIn the current implementation, func type is checked with\nbtf_func_check() in the main checking function btf_check_all_types().\nTo fix the above kasan issue, let us implement \u0027resolve\u0027 callback\nfunc type properly. The \u0027resolve\u0027 callback will be also called\nin btf_check_all_types() for func types.",
"id": "GHSA-xx7j-2fqw-vv47",
"modified": "2025-09-22T21:30:15Z",
"published": "2025-09-22T21:30:15Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49228"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/796d5666f6422ddadc938fb888044fcc16f2dbe3"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a3bcd2110c087bc62e90fddd4a93237b049d6e68"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d7e7b42f4f956f2c68ad8cda87d750093dbba737"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.