Merge "first_stage_mount: mount point must be canonical path" (4063fc4a) · Commits · e / os / android_system_core

fs_mgr/fs_mgr.cpp

+21 −12

Original line number	Diff line number	Diff line
		@@ -2266,6 +2266,26 @@ std::string fs_mgr_get_super_partition_name(int slot) {
		return LP_METADATA_DEFAULT_PARTITION_NAME;
		}

		bool fs_mgr_create_canonical_mount_point(const std::string& mount_point) {
		auto saved_errno = errno;
		auto ok = true;
		auto created_mount_point = !mkdir(mount_point.c_str(), 0755);
		std::string real_mount_point;
		if (!Realpath(mount_point, &real_mount_point)) {
		ok = false;
		PERROR << "failed to realpath(" << mount_point << ")";
		} else if (mount_point != real_mount_point) {
		ok = false;
		LERROR << "mount point is not canonical: realpath(" << mount_point << ") -> "
		<< real_mount_point;
		}
		if (!ok && created_mount_point) {
		rmdir(mount_point.c_str());
		}
		errno = saved_errno;
		return ok;
		}

		bool fs_mgr_mount_overlayfs_fstab_entry(const FstabEntry& entry) {
		auto overlayfs_valid_result = fs_mgr_overlayfs_valid();
		if (overlayfs_valid_result == OverlayfsValidResult::kNotSupported) {
		@@ -2298,18 +2318,7 @@ bool fs_mgr_mount_overlayfs_fstab_entry(const FstabEntry& entry) {
		}
		#endif // ALLOW_ADBD_DISABLE_VERITY == 0

		// Create the mount point in case it doesn't exist.
		mkdir(entry.mount_point.c_str(), 0755);

		// Ensure that mount point exists and doesn't contain symbolic link or /../.
		std::string mount_point;
		if (!Realpath(entry.mount_point, &mount_point)) {
		PERROR << __FUNCTION__ << "(): failed to realpath " << entry.mount_point;
		return false;
		}
		if (entry.mount_point != mount_point) {
		LERROR << __FUNCTION__ << "(): mount point must be a canonicalized path: realpath "
		<< entry.mount_point << " = " << mount_point;
		if (!fs_mgr_create_canonical_mount_point(entry.mount_point)) {
		return false;
		}

fs_mgr/include/fs_mgr.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -132,6 +132,10 @@ int fs_mgr_remount_userdata_into_checkpointing(android::fs_mgr::Fstab* fstab);
		// empty string
		std::string fs_mgr_find_bow_device(const std::string& block_device);

		// Creates mount point if not already existed, and checks that mount point is a
		// canonical path that doesn't contain any symbolic link or /../.
		bool fs_mgr_create_canonical_mount_point(const std::string& mount_point);

		// Like fs_mgr_do_mount_one() but for overlayfs fstab entries.
		// Unlike fs_mgr_overlayfs, mount overlayfs without upperdir and workdir, so the
		// filesystem cannot be remount read-write.

init/first_stage_mount.cpp

+4 −0

Original line number	Diff line number	Diff line
		@@ -420,6 +420,10 @@ bool FirstStageMount::MountPartition(const Fstab::iterator& begin, bool erase_sa
		*end = begin + 1;
		}

		if (!fs_mgr_create_canonical_mount_point(begin->mount_point)) {
		return false;
		}

		if (begin->fs_mgr_flags.logical) {
		if (!fs_mgr_update_logical_partition(&(*begin))) {
		return false;