CVE-2022-50883

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

bpf: Prevent decl_tag from being referenced in func_proto arg

Syzkaller managed to hit another decl_tag issue:

btf_func_proto_check kernel/bpf/btf.c:4506 [inline]

btf_check_all_types kernel/bpf/btf.c:4734 [inline]

btf_parse_type_sec+0x1175/0x1980 kernel/bpf/btf.c:4763

btf_parse kernel/bpf/btf.c:5042 [inline]

btf_new_fd+0x65a/0xb00 kernel/bpf/btf.c:6709

bpf_btf_load+0x6f/0x90 kernel/bpf/syscall.c:4342

__sys_bpf+0x50a/0x6c0 kernel/bpf/syscall.c:5034

__do_sys_bpf kernel/bpf/syscall.c:5093 [inline]

__se_sys_bpf kernel/bpf/syscall.c:5091 [inline]

__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5091

do_syscall_64+0x54/0x70 arch/x86/entry/common.c:48

This seems similar to commit ea68376c8bed ("bpf: prevent decl_tag from being

referenced in func_proto") but for the argument.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References