diff options
Diffstat (limited to 'tools/testing/selftests/cgroup/test_core.c')
| -rw-r--r-- | tools/testing/selftests/cgroup/test_core.c | 172 |
1 files changed, 171 insertions, 1 deletions
diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c index 3df648c37876..a5672a91d273 100644 --- a/tools/testing/selftests/cgroup/test_core.c +++ b/tools/testing/selftests/cgroup/test_core.c @@ -1,11 +1,14 @@ /* SPDX-License-Identifier: GPL-2.0 */ +#define _GNU_SOURCE #include <linux/limits.h> +#include <linux/sched.h> #include <sys/types.h> #include <sys/mman.h> #include <sys/wait.h> #include <unistd.h> #include <fcntl.h> +#include <sched.h> #include <stdio.h> #include <errno.h> #include <signal.h> @@ -15,6 +18,8 @@ #include "../kselftest.h" #include "cgroup_util.h" +static bool nsdelegate; + static int touch_anon(char *buf, size_t size) { int fd; @@ -674,6 +679,169 @@ cleanup: return ret; } +/* + * cgroup migration permission check should be performed based on the + * credentials at the time of open instead of write. + */ +static int test_cgcore_lesser_euid_open(const char *root) +{ + const uid_t test_euid = TEST_UID; + int ret = KSFT_FAIL; + char *cg_test_a = NULL, *cg_test_b = NULL; + char *cg_test_a_procs = NULL, *cg_test_b_procs = NULL; + int cg_test_b_procs_fd = -1; + uid_t saved_uid; + + cg_test_a = cg_name(root, "cg_test_a"); + cg_test_b = cg_name(root, "cg_test_b"); + + if (!cg_test_a || !cg_test_b) + goto cleanup; + + cg_test_a_procs = cg_name(cg_test_a, "cgroup.procs"); + cg_test_b_procs = cg_name(cg_test_b, "cgroup.procs"); + + if (!cg_test_a_procs || !cg_test_b_procs) + goto cleanup; + + if (cg_create(cg_test_a) || cg_create(cg_test_b)) + goto cleanup; + + if (cg_enter_current(cg_test_a)) + goto cleanup; + + if (chown(cg_test_a_procs, test_euid, -1) || + chown(cg_test_b_procs, test_euid, -1)) + goto cleanup; + + saved_uid = geteuid(); + if (seteuid(test_euid)) + goto cleanup; + + cg_test_b_procs_fd = open(cg_test_b_procs, O_RDWR); + + if (seteuid(saved_uid)) + goto cleanup; + + if (cg_test_b_procs_fd < 0) + goto cleanup; + + if (write(cg_test_b_procs_fd, "0", 1) >= 0 || errno != EACCES) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + cg_enter_current(root); + if (cg_test_b_procs_fd >= 0) + close(cg_test_b_procs_fd); + if (cg_test_b) + cg_destroy(cg_test_b); + if (cg_test_a) + cg_destroy(cg_test_a); + free(cg_test_b_procs); + free(cg_test_a_procs); + free(cg_test_b); + free(cg_test_a); + return ret; +} + +struct lesser_ns_open_thread_arg { + const char *path; + int fd; + int err; +}; + +static int lesser_ns_open_thread_fn(void *arg) +{ + struct lesser_ns_open_thread_arg *targ = arg; + + targ->fd = open(targ->path, O_RDWR); + targ->err = errno; + return 0; +} + +/* + * cgroup migration permission check should be performed based on the cgroup + * namespace at the time of open instead of write. + */ +static int test_cgcore_lesser_ns_open(const char *root) +{ + static char stack[65536]; + const uid_t test_euid = 65534; /* usually nobody, any !root is fine */ + int ret = KSFT_FAIL; + char *cg_test_a = NULL, *cg_test_b = NULL; + char *cg_test_a_procs = NULL, *cg_test_b_procs = NULL; + int cg_test_b_procs_fd = -1; + struct lesser_ns_open_thread_arg targ = { .fd = -1 }; + pid_t pid; + int status; + + if (!nsdelegate) + return KSFT_SKIP; + + cg_test_a = cg_name(root, "cg_test_a"); + cg_test_b = cg_name(root, "cg_test_b"); + + if (!cg_test_a || !cg_test_b) + goto cleanup; + + cg_test_a_procs = cg_name(cg_test_a, "cgroup.procs"); + cg_test_b_procs = cg_name(cg_test_b, "cgroup.procs"); + + if (!cg_test_a_procs || !cg_test_b_procs) + goto cleanup; + + if (cg_create(cg_test_a) || cg_create(cg_test_b)) + goto cleanup; + + if (cg_enter_current(cg_test_b)) + goto cleanup; + + if (chown(cg_test_a_procs, test_euid, -1) || + chown(cg_test_b_procs, test_euid, -1)) + goto cleanup; + + targ.path = cg_test_b_procs; + pid = clone(lesser_ns_open_thread_fn, stack + sizeof(stack), + CLONE_NEWCGROUP | CLONE_FILES | CLONE_VM | SIGCHLD, + &targ); + if (pid < 0) + goto cleanup; + + if (waitpid(pid, &status, 0) < 0) + goto cleanup; + + if (!WIFEXITED(status)) + goto cleanup; + + cg_test_b_procs_fd = targ.fd; + if (cg_test_b_procs_fd < 0) + goto cleanup; + + if (cg_enter_current(cg_test_a)) + goto cleanup; + + if ((status = write(cg_test_b_procs_fd, "0", 1)) >= 0 || errno != ENOENT) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + cg_enter_current(root); + if (cg_test_b_procs_fd >= 0) + close(cg_test_b_procs_fd); + if (cg_test_b) + cg_destroy(cg_test_b); + if (cg_test_a) + cg_destroy(cg_test_a); + free(cg_test_b_procs); + free(cg_test_a_procs); + free(cg_test_b); + free(cg_test_a); + return ret; +} + #define T(x) { x, #x } struct corecg_test { int (*fn)(const char *root); @@ -689,6 +857,8 @@ struct corecg_test { T(test_cgcore_proc_migration), T(test_cgcore_thread_migration), T(test_cgcore_destroy), + T(test_cgcore_lesser_euid_open), + T(test_cgcore_lesser_ns_open), }; #undef T @@ -697,7 +867,7 @@ int main(int argc, char *argv[]) char root[PATH_MAX]; int i, ret = EXIT_SUCCESS; - if (cg_find_unified_root(root, sizeof(root))) + if (cg_find_unified_root(root, sizeof(root), &nsdelegate)) ksft_exit_skip("cgroup v2 isn't mounted\n"); if (cg_read_strstr(root, "cgroup.subtree_control", "memory")) |