diff --git a/tests/sys/file/path_test.c b/tests/sys/file/path_test.c index a212325c7db6..130acababb21 100644 --- a/tests/sys/file/path_test.c +++ b/tests/sys/file/path_test.c @@ -208,6 +208,80 @@ ATF_TC_BODY(path_capsicum, tc) waitchild(child, 4); } +/* + * Check that a pathfd can be converted to a regular fd using openat() in + * capability mode, but that rights on the pathfd are respected. + */ +ATF_TC_WITHOUT_HEAD(path_capsicum_empty); +ATF_TC_BODY(path_capsicum_empty, tc) +{ + char path[PATH_MAX]; + cap_rights_t rights; + int dfd, fd, pathfd, pathdfd; + + mktfile(path, "path_capsicum.XXXXXX"); + + pathdfd = open(".", O_PATH); + ATF_REQUIRE_MSG(pathdfd >= 0, FMT_ERR("open")); + pathfd = open(path, O_PATH); + ATF_REQUIRE_MSG(pathfd >= 0, FMT_ERR("open")); + + ATF_REQUIRE(cap_enter() == 0); + + dfd = openat(pathdfd, "", O_DIRECTORY | O_EMPTY_PATH); + ATF_REQUIRE(dfd >= 0); + CHECKED_CLOSE(dfd); + + /* + * CAP_READ and CAP_LOOKUP should be sufficient to open a directory. + */ + cap_rights_init(&rights, CAP_READ | CAP_LOOKUP); + ATF_REQUIRE(cap_rights_limit(pathdfd, &rights) == 0); + dfd = openat(pathdfd, "", O_DIRECTORY | O_EMPTY_PATH); + ATF_REQUIRE(dfd >= 0); + CHECKED_CLOSE(dfd); + + /* + * ... CAP_READ on its own is not. + */ + cap_rights_init(&rights, CAP_READ); + ATF_REQUIRE(cap_rights_limit(pathdfd, &rights) == 0); + dfd = openat(pathdfd, "", O_DIRECTORY | O_EMPTY_PATH); + ATF_REQUIRE_ERRNO(ENOTCAPABLE, dfd == -1); + + /* + * Now try with a regular file. + */ + fd = openat(pathfd, "", O_RDWR | O_EMPTY_PATH); + ATF_REQUIRE(fd >= 0); + CHECKED_CLOSE(fd); + + cap_rights_init(&rights, CAP_READ | CAP_LOOKUP | CAP_WRITE); + ATF_REQUIRE(cap_rights_limit(pathfd, &rights) == 0); + fd = openat(pathfd, "", O_RDWR | O_EMPTY_PATH | O_APPEND); + ATF_REQUIRE(fd >= 0); + CHECKED_CLOSE(fd); + + /* + * CAP_SEEK is needed to open a file for writing without O_APPEND. + */ + cap_rights_init(&rights, CAP_READ | CAP_LOOKUP | CAP_WRITE); + ATF_REQUIRE(cap_rights_limit(pathfd, &rights) == 0); + fd = openat(pathfd, "", O_RDWR | O_EMPTY_PATH); + ATF_REQUIRE_ERRNO(ENOTCAPABLE, fd == -1); + + /* + * CAP_LOOKUP isn't sufficient to open a file for reading. + */ + cap_rights_init(&rights, CAP_LOOKUP); + ATF_REQUIRE(cap_rights_limit(pathfd, &rights) == 0); + fd = openat(pathfd, "", O_RDONLY | O_EMPTY_PATH); + ATF_REQUIRE_ERRNO(ENOTCAPABLE, fd == -1); + + CHECKED_CLOSE(pathfd); + CHECKED_CLOSE(pathdfd); +} + /* Make sure that ptrace(PT_COREDUMP) cannot be used to write to a path fd. */ ATF_TC_WITHOUT_HEAD(path_coredump); ATF_TC_BODY(path_coredump, tc) @@ -937,6 +1011,7 @@ ATF_TP_ADD_TCS(tp) ATF_TP_ADD_TC(tp, path_access); ATF_TP_ADD_TC(tp, path_aio); ATF_TP_ADD_TC(tp, path_capsicum); + ATF_TP_ADD_TC(tp, path_capsicum_empty); ATF_TP_ADD_TC(tp, path_coredump); ATF_TP_ADD_TC(tp, path_directory); ATF_TP_ADD_TC(tp, path_directory_not_root);