| 1 | |
| 2 | |
| 3 | * Linux Security Module infrastructure tests
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| 4 | *
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| 5 | * Copyright © 2023 Casey Schaufler <[email protected]>
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| 6 |
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| 7 |
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| 8 | #define _GNU_SOURCE
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| 9 | #include <linux/lsm.h>
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| 10 | #include <fcntl.h>
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| 11 | #include <string.h>
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| 12 | #include <stdio.h>
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| 13 | #include <stdlib.h>
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| 14 | #include <unistd.h>
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| 15 | #include <sys/types.h>
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| 16 | #include "common.h"
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| 17 |
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| 18 | #define PROCATTR "/proc/self/attr/"
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| 19 |
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| 20 | int read_proc_attr(const char *attr, char *value, size_t size)
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| 21 | {
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| 22 | int fd;
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| 23 | int len;
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| 24 | char *path;
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| 25 |
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| 26 | len = strlen(PROCATTR) + strlen(attr) + 1;
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| 27 | path = calloc(len, 1);
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| 28 | if (path == NULL)
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| 29 | return -1;
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| 30 | sprintf(path, "%s%s", PROCATTR, attr);
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| 31 |
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| 32 | fd = open(path, O_RDONLY);
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| 33 | free(path);
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| 34 |
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| 35 | if (fd < 0)
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| 36 | return -1;
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| 37 | len = read(fd, value, size);
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| 38 |
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| 39 | close(fd);
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| 40 |
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| 41 |
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| 42 | if (len <= 0 || len == size)
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| 43 | return -1;
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| 44 | value[len] = '\0';
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| 45 |
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| 46 | path = strchr(value, '\n');
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| 47 | if (path)
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| 48 | *path = '\0';
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| 49 |
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| 50 | return 0;
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| 51 | }
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| 52 |
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| 53 | int read_sysfs_lsms(char *lsms, size_t size)
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| 54 | {
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| 55 | FILE *fp;
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| 56 | size_t red;
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| 57 |
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| 58 | fp = fopen("/sys/kernel/security/lsm", "r");
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| 59 | if (fp == NULL)
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| 60 | return -1;
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| 61 | red = fread(lsms, 1, size, fp);
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| 62 | fclose(fp);
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| 63 |
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| 64 | if (red <= 0 || red == size)
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| 65 | return -1;
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| 66 | lsms[red] = '\0';
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| 67 | return 0;
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| 68 | }
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| 69 |
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| 70 | int attr_lsm_count(void)
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| 71 | {
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| 72 | char *names = calloc(sysconf(_SC_PAGESIZE), 1);
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| 73 | int count = 0;
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| 74 |
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| 75 | if (!names)
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| 76 | return 0;
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| 77 |
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| 78 | if (read_sysfs_lsms(names, sysconf(_SC_PAGESIZE)))
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| 79 | goto out;
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| 80 |
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| 81 | if (strstr(names, "selinux"))
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| 82 | count++;
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| 83 | if (strstr(names, "smack"))
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| 84 | count++;
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| 85 | if (strstr(names, "apparmor"))
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| 86 | count++;
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| 87 |
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| 88 | out:
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| 89 | free(names);
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| 90 | return count;
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| 91 | }
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