From 4e7301e6df9595e34e52acc18b943d00c4865e3d Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Tue, 14 May 2019 15:44:43 -0700 Subject: exec selftests: test ->recursion_depth Test that trivially recursing script onto itself doesn't work. Note: this is different test from ELOOP tests in execveat.c Those test that execveat(2) doesn't follow symlinks when told to do so. Link: http://lkml.kernel.org/r/20190423192720.GA21433@avx2 Signed-off-by: Alexey Dobriyan Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- tools/testing/selftests/exec/.gitignore | 3 +- tools/testing/selftests/exec/Makefile | 4 ++ tools/testing/selftests/exec/recursion-depth.c | 67 ++++++++++++++++++++++++++ 3 files changed, 73 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/exec/recursion-depth.c (limited to 'tools/testing/selftests') diff --git a/tools/testing/selftests/exec/.gitignore b/tools/testing/selftests/exec/.gitignore index 64073e050c6a..b02279da6fa1 100644 --- a/tools/testing/selftests/exec/.gitignore +++ b/tools/testing/selftests/exec/.gitignore @@ -6,4 +6,5 @@ execveat.moved execveat.path.ephemeral execveat.ephemeral execveat.denatured -xxxxxxxx* \ No newline at end of file +/recursion-depth +xxxxxxxx* diff --git a/tools/testing/selftests/exec/Makefile b/tools/testing/selftests/exec/Makefile index 427c41ba5151..33339e31e365 100644 --- a/tools/testing/selftests/exec/Makefile +++ b/tools/testing/selftests/exec/Makefile @@ -1,11 +1,15 @@ # SPDX-License-Identifier: GPL-2.0 CFLAGS = -Wall +CFLAGS += -Wno-nonnull +CFLAGS += -D_GNU_SOURCE TEST_GEN_PROGS := execveat TEST_GEN_FILES := execveat.symlink execveat.denatured script subdir # Makefile is a run-time dependency, since it's accessed by the execveat test TEST_FILES := Makefile +TEST_GEN_PROGS += recursion-depth + EXTRA_CLEAN := $(OUTPUT)/subdir.moved $(OUTPUT)/execveat.moved $(OUTPUT)/xxxxx* include ../lib.mk diff --git a/tools/testing/selftests/exec/recursion-depth.c b/tools/testing/selftests/exec/recursion-depth.c new file mode 100644 index 000000000000..2dbd5bc45b3e --- /dev/null +++ b/tools/testing/selftests/exec/recursion-depth.c @@ -0,0 +1,67 @@ +/* + * Copyright (c) 2019 Alexey Dobriyan + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ +/* Test that pointing #! script interpreter to self doesn't recurse. */ +#include +#include +#include +#include +#include +#include +#include +#include +#include + +int main(void) +{ + if (unshare(CLONE_NEWNS) == -1) { + if (errno == ENOSYS || errno == EPERM) { + fprintf(stderr, "error: unshare, errno %d\n", errno); + return 4; + } + fprintf(stderr, "error: unshare, errno %d\n", errno); + return 1; + } + if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) { + fprintf(stderr, "error: mount '/', errno %d\n", errno); + return 1; + } + /* Require "exec" filesystem. */ + if (mount(NULL, "/tmp", "ramfs", 0, NULL) == -1) { + fprintf(stderr, "error: mount ramfs, errno %d\n", errno); + return 1; + } + +#define FILENAME "/tmp/1" + + int fd = creat(FILENAME, 0700); + if (fd == -1) { + fprintf(stderr, "error: creat, errno %d\n", errno); + return 1; + } +#define S "#!" FILENAME "\n" + if (write(fd, S, strlen(S)) != strlen(S)) { + fprintf(stderr, "error: write, errno %d\n", errno); + return 1; + } + close(fd); + + int rv = execve(FILENAME, NULL, NULL); + if (rv == -1 && errno == ELOOP) { + return 0; + } + fprintf(stderr, "error: execve, rv %d, errno %d\n", rv, errno); + return 1; +} -- cgit v1.2.3-59-g8ed1b