{"cve":"CVE-2022-49228","nvd":{"published":"2025-02-26T07:00:59.840","modified":"2026-06-17T05:17:26.820","status":"Analyzed","description":"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   <TASK>\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 'resolve' callback functions\nand hence handled properly in kernel.\nBut func type doesn't have 'resolve' 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 'resolve' callback\nfunc type properly. The 'resolve' callback will be also called\nin btf_check_all_types() for func types.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/796d5666f6422ddadc938fb888044fcc16f2dbe3","https://git.kernel.org/stable/c/a3bcd2110c087bc62e90fddd4a93237b049d6e68","https://git.kernel.org/stable/c/d7e7b42f4f956f2c68ad8cda87d750093dbba737"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:59:48.811064707+00:00"},"epss":{"cve":"CVE-2022-49228","score":0.00258,"percentile":0.17558,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}