| // SPDX-License-Identifier: GPL-2.0 |
| #include <linux/bpf.h> |
| #include <bpf/bpf_helpers.h> |
| #include <bpf/bpf_tracing.h> |
| #include <errno.h> |
| #include <linux/capability.h> |
| |
| typedef struct { unsigned long long val; } kernel_cap_t; |
| |
| struct cred { |
| kernel_cap_t cap_effective; |
| } __attribute__((preserve_access_index)); |
| |
| char _license[] SEC("license") = "GPL"; |
| |
| SEC("lsm.s/userns_create") |
| int BPF_PROG(test_userns_create, const struct cred *cred, int ret) |
| { |
| kernel_cap_t caps = cred->cap_effective; |
| __u64 cap_mask = 1ULL << CAP_SYS_ADMIN; |
| |
| if (ret) |
| return 0; |
| |
| ret = -EPERM; |
| if (caps.val & cap_mask) |
| return 0; |
| |
| return -EPERM; |
| } |
