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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 02:25:50 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 02:25:50 +0000 |
commit | 19f4f86bfed21c5326ed2acebe1163f3a83e832b (patch) | |
tree | d59b9989ce55ed23693e80974d94c856f1c2c8b1 /src/fuzz/fuzz-udev-rules.c | |
parent | Initial commit. (diff) | |
download | systemd-upstream.tar.xz systemd-upstream.zip |
Adding upstream version 241.upstream/241upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/fuzz/fuzz-udev-rules.c')
-rw-r--r-- | src/fuzz/fuzz-udev-rules.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/src/fuzz/fuzz-udev-rules.c b/src/fuzz/fuzz-udev-rules.c new file mode 100644 index 0000000..e894fa8 --- /dev/null +++ b/src/fuzz/fuzz-udev-rules.c @@ -0,0 +1,107 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include <errno.h> +#include <sched.h> +#include <sys/mount.h> +#include <unistd.h> + +#include "fd-util.h" +#include "fs-util.h" +#include "fuzz.h" +#include "log.h" +#include "mkdir.h" +#include "missing.h" +#include "rm-rf.h" +#include "string-util.h" +#include "tests.h" +#include "udev.h" + +static struct fakefs { + const char *target; + bool ignore_mount_error; + bool is_mounted; +} fakefss[] = { + { "/sys", false, false }, + { "/dev", false, false }, + { "/run", false, false }, + { "/etc", false, false }, + { UDEVLIBEXECDIR "/rules.d", true, false }, +}; + +static int setup_mount_namespace(void) { + static thread_local bool is_namespaced = false; + + if (is_namespaced) + return 1; + + if (unshare(CLONE_NEWNS) < 0) + return log_error_errno(errno, "Failed to call unshare(): %m"); + + if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) + return log_error_errno(errno, "Failed to mount / as private: %m"); + + is_namespaced = true; + + return 1; +} + +static int setup_fake_filesystems(const char *runtime_dir) { + for (unsigned i = 0; i < ELEMENTSOF(fakefss); i++) { + if (mount(runtime_dir, fakefss[i].target, NULL, MS_BIND, NULL) < 0) { + log_full_errno(fakefss[i].ignore_mount_error ? LOG_DEBUG : LOG_ERR, errno, "Failed to mount %s: %m", fakefss[i].target); + if (!fakefss[i].ignore_mount_error) + return -errno; + } else + fakefss[i].is_mounted = true; + } + + return 0; +} + +static int cleanup_fake_filesystems(const char *runtime_dir) { + for (unsigned i = 0; i < ELEMENTSOF(fakefss); i++) { + if (!fakefss[i].is_mounted) + continue; + + if (umount(fakefss[i].target) < 0) { + log_full_errno(fakefss[i].ignore_mount_error ? LOG_DEBUG : LOG_ERR, errno, "Failed to umount %s: %m", fakefss[i].target); + if (!fakefss[i].ignore_mount_error) + return -errno; + } else + fakefss[i].is_mounted = false; + } + return 0; +} + +int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) { + _cleanup_(udev_rules_freep) UdevRules *rules = NULL; + _cleanup_(rm_rf_physical_and_freep) char *runtime_dir = NULL; + FILE *f = NULL; + + (void) setup_mount_namespace(); + + assert_se(runtime_dir = setup_fake_runtime_dir()); + + if (setup_fake_filesystems(runtime_dir) < 0) { +#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION + return EXIT_TEST_SKIP; +#endif + } + + if (!getenv("SYSTEMD_LOG_LEVEL")) { + log_set_max_level_realm(LOG_REALM_UDEV, LOG_CRIT); + log_set_max_level_realm(LOG_REALM_SYSTEMD, LOG_CRIT); + } + + assert_se(mkdir_p("/etc/udev/rules.d", 0755) >= 0); + f = fopen("/etc/udev/rules.d/fuzz.rules", "we"); + assert_se(f); + if (size != 0) + assert_se(fwrite(data, size, 1, f) == 1); + assert_se(fclose(f) == 0); + + assert_se(udev_rules_new(&rules, RESOLVE_NAME_EARLY) == 0); + + assert_se(cleanup_fake_filesystems(runtime_dir) >= 0); + return 0; +} |