From 4893992b6de1be5e0c9f6df747912761e96b4271 Mon Sep 17 00:00:00 2001 From: Muhammad Usama Anjum Date: Fri, 11 Feb 2022 03:23:19 +0500 Subject: selftests/exec: Rename file binfmt_script to binfmt_script.py Rename file for readability purpose. Update its usage and references. Signed-off-by: Muhammad Usama Anjum Reviewed-by: Kees Cook Signed-off-by: Shuah Khan --- tools/testing/selftests/exec/Makefile | 2 +- tools/testing/selftests/exec/binfmt_script | 171 -------------------------- tools/testing/selftests/exec/binfmt_script.py | 171 ++++++++++++++++++++++++++ 3 files changed, 172 insertions(+), 172 deletions(-) delete mode 100755 tools/testing/selftests/exec/binfmt_script create mode 100755 tools/testing/selftests/exec/binfmt_script.py (limited to 'tools/testing/selftests/exec') diff --git a/tools/testing/selftests/exec/Makefile b/tools/testing/selftests/exec/Makefile index 2d7fca446c7f..7f0412a26ba9 100644 --- a/tools/testing/selftests/exec/Makefile +++ b/tools/testing/selftests/exec/Makefile @@ -3,7 +3,7 @@ CFLAGS = -Wall CFLAGS += -Wno-nonnull CFLAGS += -D_GNU_SOURCE -TEST_PROGS := binfmt_script +TEST_PROGS := binfmt_script.py TEST_GEN_PROGS := execveat load_address_4096 load_address_2097152 load_address_16777216 non-regular TEST_GEN_FILES := execveat.symlink execveat.denatured script subdir # Makefile is a run-time dependency, since it's accessed by the execveat test diff --git a/tools/testing/selftests/exec/binfmt_script b/tools/testing/selftests/exec/binfmt_script deleted file mode 100755 index 05f94a741c7a..000000000000 --- a/tools/testing/selftests/exec/binfmt_script +++ /dev/null @@ -1,171 +0,0 @@ -#!/usr/bin/env python3 -# SPDX-License-Identifier: GPL-2.0 -# -# Test that truncation of bprm->buf doesn't cause unexpected execs paths, along -# with various other pathological cases. -import os, subprocess - -# Relevant commits -# -# b5372fe5dc84 ("exec: load_script: Do not exec truncated interpreter path") -# 6eb3c3d0a52d ("exec: increase BINPRM_BUF_SIZE to 256") - -# BINPRM_BUF_SIZE -SIZE=256 - -NAME_MAX=int(subprocess.check_output(["getconf", "NAME_MAX", "."])) - -test_num=0 - -code='''#!/usr/bin/perl -print "Executed interpreter! Args:\n"; -print "0 : '$0'\n"; -$counter = 1; -foreach my $a (@ARGV) { - print "$counter : '$a'\n"; - $counter++; -} -''' - -## -# test - produce a binfmt_script hashbang line for testing -# -# @size: bytes for bprm->buf line, including hashbang but not newline -# @good: whether this script is expected to execute correctly -# @hashbang: the special 2 bytes for running binfmt_script -# @leading: any leading whitespace before the executable path -# @root: start of executable pathname -# @target: end of executable pathname -# @arg: bytes following the executable pathname -# @fill: character to fill between @root and @target to reach @size bytes -# @newline: character to use as newline, not counted towards @size -# ... -def test(name, size, good=True, leading="", root="./", target="/perl", - fill="A", arg="", newline="\n", hashbang="#!"): - global test_num, tests, NAME_MAX - test_num += 1 - if test_num > tests: - raise ValueError("more binfmt_script tests than expected! (want %d, expected %d)" - % (test_num, tests)) - - middle = "" - remaining = size - len(hashbang) - len(leading) - len(root) - len(target) - len(arg) - # The middle of the pathname must not exceed NAME_MAX - while remaining >= NAME_MAX: - middle += fill * (NAME_MAX - 1) - middle += '/' - remaining -= NAME_MAX - middle += fill * remaining - - dirpath = root + middle - binary = dirpath + target - if len(target): - os.makedirs(dirpath, mode=0o755, exist_ok=True) - open(binary, "w").write(code) - os.chmod(binary, 0o755) - - buf=hashbang + leading + root + middle + target + arg + newline - if len(newline) > 0: - buf += 'echo this is not really perl\n' - - script = "binfmt_script-%s" % (name) - open(script, "w").write(buf) - os.chmod(script, 0o755) - - proc = subprocess.Popen(["./%s" % (script)], shell=True, - stdout=subprocess.PIPE, stderr=subprocess.STDOUT) - stdout = proc.communicate()[0] - - if proc.returncode == 0 and b'Executed interpreter' in stdout: - if good: - print("ok %d - binfmt_script %s (successful good exec)" - % (test_num, name)) - else: - print("not ok %d - binfmt_script %s succeeded when it should have failed" - % (test_num, name)) - else: - if good: - print("not ok %d - binfmt_script %s failed when it should have succeeded (rc:%d)" - % (test_num, name, proc.returncode)) - else: - print("ok %d - binfmt_script %s (correctly failed bad exec)" - % (test_num, name)) - - # Clean up crazy binaries - os.unlink(script) - if len(target): - elements = binary.split('/') - os.unlink(binary) - elements.pop() - while len(elements) > 1: - os.rmdir("/".join(elements)) - elements.pop() - -tests=27 -print("TAP version 1.3") -print("1..%d" % (tests)) - -### FAIL (8 tests) - -# Entire path is well past the BINFMT_BUF_SIZE. -test(name="too-big", size=SIZE+80, good=False) -# Path is right at max size, making it impossible to tell if it was truncated. -test(name="exact", size=SIZE, good=False) -# Same as above, but with leading whitespace. -test(name="exact-space", size=SIZE, good=False, leading=" ") -# Huge buffer of only whitespace. -test(name="whitespace-too-big", size=SIZE+71, good=False, root="", - fill=" ", target="") -# A good path, but it gets truncated due to leading whitespace. -test(name="truncated", size=SIZE+17, good=False, leading=" " * 19) -# Entirely empty except for #! -test(name="empty", size=2, good=False, root="", - fill="", target="", newline="") -# Within size, but entirely spaces -test(name="spaces", size=SIZE-1, good=False, root="", fill=" ", - target="", newline="") -# Newline before binary. -test(name="newline-prefix", size=SIZE-1, good=False, leading="\n", - root="", fill=" ", target="") - -### ok (19 tests) - -# The original test case that was broken by commit: -# 8099b047ecc4 ("exec: load_script: don't blindly truncate shebang string") -test(name="test.pl", size=439, leading=" ", - root="./nix/store/bwav8kz8b3y471wjsybgzw84mrh4js9-perl-5.28.1/bin", - arg=" -I/nix/store/x6yyav38jgr924nkna62q3pkp0dgmzlx-perl5.28.1-File-Slurp-9999.25/lib/perl5/site_perl -I/nix/store/ha8v67sl8dac92r9z07vzr4gv1y9nwqz-perl5.28.1-Net-DBus-1.1.0/lib/perl5/site_perl -I/nix/store/dcrkvnjmwh69ljsvpbdjjdnqgwx90a9d-perl5.28.1-XML-Parser-2.44/lib/perl5/site_perl -I/nix/store/rmji88k2zz7h4zg97385bygcydrf2q8h-perl5.28.1-XML-Twig-3.52/lib/perl5/site_perl") -# One byte under size, leaving newline visible. -test(name="one-under", size=SIZE-1) -# Two bytes under size, leaving newline visible. -test(name="two-under", size=SIZE-2) -# Exact size, but trailing whitespace visible instead of newline -test(name="exact-trunc-whitespace", size=SIZE, arg=" ") -# Exact size, but trailing space and first arg char visible instead of newline. -test(name="exact-trunc-arg", size=SIZE, arg=" f") -# One bute under, with confirmed non-truncated arg since newline now visible. -test(name="one-under-full-arg", size=SIZE-1, arg=" f") -# Short read buffer by one byte. -test(name="one-under-no-nl", size=SIZE-1, newline="") -# Short read buffer by half buffer size. -test(name="half-under-no-nl", size=int(SIZE/2), newline="") -# One byte under with whitespace arg. leaving wenline visible. -test(name="one-under-trunc-arg", size=SIZE-1, arg=" ") -# One byte under with whitespace leading. leaving wenline visible. -test(name="one-under-leading", size=SIZE-1, leading=" ") -# One byte under with whitespace leading and as arg. leaving newline visible. -test(name="one-under-leading-trunc-arg", size=SIZE-1, leading=" ", arg=" ") -# Same as above, but with 2 bytes under -test(name="two-under-no-nl", size=SIZE-2, newline="") -test(name="two-under-trunc-arg", size=SIZE-2, arg=" ") -test(name="two-under-leading", size=SIZE-2, leading=" ") -test(name="two-under-leading-trunc-arg", size=SIZE-2, leading=" ", arg=" ") -# Same as above, but with buffer half filled -test(name="two-under-no-nl", size=int(SIZE/2), newline="") -test(name="two-under-trunc-arg", size=int(SIZE/2), arg=" ") -test(name="two-under-leading", size=int(SIZE/2), leading=" ") -test(name="two-under-lead-trunc-arg", size=int(SIZE/2), leading=" ", arg=" ") - -if test_num != tests: - raise ValueError("fewer binfmt_script tests than expected! (ran %d, expected %d" - % (test_num, tests)) diff --git a/tools/testing/selftests/exec/binfmt_script.py b/tools/testing/selftests/exec/binfmt_script.py new file mode 100755 index 000000000000..05f94a741c7a --- /dev/null +++ b/tools/testing/selftests/exec/binfmt_script.py @@ -0,0 +1,171 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0 +# +# Test that truncation of bprm->buf doesn't cause unexpected execs paths, along +# with various other pathological cases. +import os, subprocess + +# Relevant commits +# +# b5372fe5dc84 ("exec: load_script: Do not exec truncated interpreter path") +# 6eb3c3d0a52d ("exec: increase BINPRM_BUF_SIZE to 256") + +# BINPRM_BUF_SIZE +SIZE=256 + +NAME_MAX=int(subprocess.check_output(["getconf", "NAME_MAX", "."])) + +test_num=0 + +code='''#!/usr/bin/perl +print "Executed interpreter! Args:\n"; +print "0 : '$0'\n"; +$counter = 1; +foreach my $a (@ARGV) { + print "$counter : '$a'\n"; + $counter++; +} +''' + +## +# test - produce a binfmt_script hashbang line for testing +# +# @size: bytes for bprm->buf line, including hashbang but not newline +# @good: whether this script is expected to execute correctly +# @hashbang: the special 2 bytes for running binfmt_script +# @leading: any leading whitespace before the executable path +# @root: start of executable pathname +# @target: end of executable pathname +# @arg: bytes following the executable pathname +# @fill: character to fill between @root and @target to reach @size bytes +# @newline: character to use as newline, not counted towards @size +# ... +def test(name, size, good=True, leading="", root="./", target="/perl", + fill="A", arg="", newline="\n", hashbang="#!"): + global test_num, tests, NAME_MAX + test_num += 1 + if test_num > tests: + raise ValueError("more binfmt_script tests than expected! (want %d, expected %d)" + % (test_num, tests)) + + middle = "" + remaining = size - len(hashbang) - len(leading) - len(root) - len(target) - len(arg) + # The middle of the pathname must not exceed NAME_MAX + while remaining >= NAME_MAX: + middle += fill * (NAME_MAX - 1) + middle += '/' + remaining -= NAME_MAX + middle += fill * remaining + + dirpath = root + middle + binary = dirpath + target + if len(target): + os.makedirs(dirpath, mode=0o755, exist_ok=True) + open(binary, "w").write(code) + os.chmod(binary, 0o755) + + buf=hashbang + leading + root + middle + target + arg + newline + if len(newline) > 0: + buf += 'echo this is not really perl\n' + + script = "binfmt_script-%s" % (name) + open(script, "w").write(buf) + os.chmod(script, 0o755) + + proc = subprocess.Popen(["./%s" % (script)], shell=True, + stdout=subprocess.PIPE, stderr=subprocess.STDOUT) + stdout = proc.communicate()[0] + + if proc.returncode == 0 and b'Executed interpreter' in stdout: + if good: + print("ok %d - binfmt_script %s (successful good exec)" + % (test_num, name)) + else: + print("not ok %d - binfmt_script %s succeeded when it should have failed" + % (test_num, name)) + else: + if good: + print("not ok %d - binfmt_script %s failed when it should have succeeded (rc:%d)" + % (test_num, name, proc.returncode)) + else: + print("ok %d - binfmt_script %s (correctly failed bad exec)" + % (test_num, name)) + + # Clean up crazy binaries + os.unlink(script) + if len(target): + elements = binary.split('/') + os.unlink(binary) + elements.pop() + while len(elements) > 1: + os.rmdir("/".join(elements)) + elements.pop() + +tests=27 +print("TAP version 1.3") +print("1..%d" % (tests)) + +### FAIL (8 tests) + +# Entire path is well past the BINFMT_BUF_SIZE. +test(name="too-big", size=SIZE+80, good=False) +# Path is right at max size, making it impossible to tell if it was truncated. +test(name="exact", size=SIZE, good=False) +# Same as above, but with leading whitespace. +test(name="exact-space", size=SIZE, good=False, leading=" ") +# Huge buffer of only whitespace. +test(name="whitespace-too-big", size=SIZE+71, good=False, root="", + fill=" ", target="") +# A good path, but it gets truncated due to leading whitespace. +test(name="truncated", size=SIZE+17, good=False, leading=" " * 19) +# Entirely empty except for #! +test(name="empty", size=2, good=False, root="", + fill="", target="", newline="") +# Within size, but entirely spaces +test(name="spaces", size=SIZE-1, good=False, root="", fill=" ", + target="", newline="") +# Newline before binary. +test(name="newline-prefix", size=SIZE-1, good=False, leading="\n", + root="", fill=" ", target="") + +### ok (19 tests) + +# The original test case that was broken by commit: +# 8099b047ecc4 ("exec: load_script: don't blindly truncate shebang string") +test(name="test.pl", size=439, leading=" ", + root="./nix/store/bwav8kz8b3y471wjsybgzw84mrh4js9-perl-5.28.1/bin", + arg=" -I/nix/store/x6yyav38jgr924nkna62q3pkp0dgmzlx-perl5.28.1-File-Slurp-9999.25/lib/perl5/site_perl -I/nix/store/ha8v67sl8dac92r9z07vzr4gv1y9nwqz-perl5.28.1-Net-DBus-1.1.0/lib/perl5/site_perl -I/nix/store/dcrkvnjmwh69ljsvpbdjjdnqgwx90a9d-perl5.28.1-XML-Parser-2.44/lib/perl5/site_perl -I/nix/store/rmji88k2zz7h4zg97385bygcydrf2q8h-perl5.28.1-XML-Twig-3.52/lib/perl5/site_perl") +# One byte under size, leaving newline visible. +test(name="one-under", size=SIZE-1) +# Two bytes under size, leaving newline visible. +test(name="two-under", size=SIZE-2) +# Exact size, but trailing whitespace visible instead of newline +test(name="exact-trunc-whitespace", size=SIZE, arg=" ") +# Exact size, but trailing space and first arg char visible instead of newline. +test(name="exact-trunc-arg", size=SIZE, arg=" f") +# One bute under, with confirmed non-truncated arg since newline now visible. +test(name="one-under-full-arg", size=SIZE-1, arg=" f") +# Short read buffer by one byte. +test(name="one-under-no-nl", size=SIZE-1, newline="") +# Short read buffer by half buffer size. +test(name="half-under-no-nl", size=int(SIZE/2), newline="") +# One byte under with whitespace arg. leaving wenline visible. +test(name="one-under-trunc-arg", size=SIZE-1, arg=" ") +# One byte under with whitespace leading. leaving wenline visible. +test(name="one-under-leading", size=SIZE-1, leading=" ") +# One byte under with whitespace leading and as arg. leaving newline visible. +test(name="one-under-leading-trunc-arg", size=SIZE-1, leading=" ", arg=" ") +# Same as above, but with 2 bytes under +test(name="two-under-no-nl", size=SIZE-2, newline="") +test(name="two-under-trunc-arg", size=SIZE-2, arg=" ") +test(name="two-under-leading", size=SIZE-2, leading=" ") +test(name="two-under-leading-trunc-arg", size=SIZE-2, leading=" ", arg=" ") +# Same as above, but with buffer half filled +test(name="two-under-no-nl", size=int(SIZE/2), newline="") +test(name="two-under-trunc-arg", size=int(SIZE/2), arg=" ") +test(name="two-under-leading", size=int(SIZE/2), leading=" ") +test(name="two-under-lead-trunc-arg", size=int(SIZE/2), leading=" ", arg=" ") + +if test_num != tests: + raise ValueError("fewer binfmt_script tests than expected! (ran %d, expected %d" + % (test_num, tests)) -- cgit From 9132c3947b09a6c67372424ff69f867f2cee82f8 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 31 Jan 2022 17:16:37 -0800 Subject: selftests/exec: Test for empty string on NULL argv Test for the NULL argv argument producing a single empty string on exec. Cc: Eric Biederman Cc: Shuah Khan Cc: Yang Yingliang Cc: Andrew Morton Cc: linux-kselftest@vger.kernel.org Signed-off-by: Kees Cook Link: https://lore.kernel.org/lkml/20220201011637.2457646-1-keescook@chromium.org --- tools/testing/selftests/exec/Makefile | 1 + tools/testing/selftests/exec/null-argv.c | 78 ++++++++++++++++++++++++++++++++ 2 files changed, 79 insertions(+) create mode 100644 tools/testing/selftests/exec/null-argv.c (limited to 'tools/testing/selftests/exec') diff --git a/tools/testing/selftests/exec/Makefile b/tools/testing/selftests/exec/Makefile index 12c5e27d32c1..551affb437fe 100644 --- a/tools/testing/selftests/exec/Makefile +++ b/tools/testing/selftests/exec/Makefile @@ -10,6 +10,7 @@ TEST_GEN_FILES := execveat.symlink execveat.denatured script subdir TEST_FILES := Makefile TEST_GEN_PROGS += recursion-depth +TEST_GEN_PROGS += null-argv EXTRA_CLEAN := $(OUTPUT)/subdir.moved $(OUTPUT)/execveat.moved $(OUTPUT)/xxxxx* \ $(OUTPUT)/S_I*.test diff --git a/tools/testing/selftests/exec/null-argv.c b/tools/testing/selftests/exec/null-argv.c new file mode 100644 index 000000000000..c19726e710d1 --- /dev/null +++ b/tools/testing/selftests/exec/null-argv.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Test that empty argvs are swapped out for a single empty string. */ +#include +#include +#include +#include + +#include "../kselftest.h" + +#define FORK(exec) \ +do { \ + pid = fork(); \ + if (pid == 0) { \ + /* Child */ \ + exec; /* Some kind of exec */ \ + perror("# " #exec); \ + return 1; \ + } \ + check_result(pid, #exec); \ +} while (0) + +void check_result(pid_t pid, const char *msg) +{ + int wstatus; + + if (pid == (pid_t)-1) { + perror("# fork"); + ksft_test_result_fail("fork failed: %s\n", msg); + return; + } + if (waitpid(pid, &wstatus, 0) < 0) { + perror("# waitpid"); + ksft_test_result_fail("waitpid failed: %s\n", msg); + return; + } + if (!WIFEXITED(wstatus)) { + ksft_test_result_fail("child did not exit: %s\n", msg); + return; + } + if (WEXITSTATUS(wstatus) != 0) { + ksft_test_result_fail("non-zero exit: %s\n", msg); + return; + } + ksft_test_result_pass("%s\n", msg); +} + +int main(int argc, char *argv[], char *envp[]) +{ + pid_t pid; + static char * const args[] = { NULL }; + static char * const str[] = { "", NULL }; + + /* argc counting checks */ + if (argc < 1) { + fprintf(stderr, "# FAIL: saw argc == 0 (old kernel?)\n"); + return 1; + } + if (argc != 1) { + fprintf(stderr, "# FAIL: unknown argc (%d)\n", argc); + return 1; + } + if (argv[0][0] == '\0') { + /* Good, we found a NULL terminated string at argv[0]! */ + return 0; + } + + /* Test runner. */ + ksft_print_header(); + ksft_set_plan(5); + + FORK(execve(argv[0], str, NULL)); + FORK(execve(argv[0], NULL, NULL)); + FORK(execve(argv[0], NULL, envp)); + FORK(execve(argv[0], args, NULL)); + FORK(execve(argv[0], args, envp)); + + ksft_exit(ksft_cnt.ksft_pass == ksft_plan); +} -- cgit From c7b9c68fc01b468983c8f4745f400fa74c831005 Mon Sep 17 00:00:00 2001 From: Muhammad Usama Anjum Date: Wed, 2 Mar 2022 23:01:19 +0500 Subject: selftests/exec: add generated files to .gitignore Add generated files non-regular and null-argv to .gitignore file. Signed-off-by: Muhammad Usama Anjum Reviewed-by: Kees Cook Signed-off-by: Shuah Khan --- tools/testing/selftests/exec/.gitignore | 2 ++ 1 file changed, 2 insertions(+) (limited to 'tools/testing/selftests/exec') diff --git a/tools/testing/selftests/exec/.gitignore b/tools/testing/selftests/exec/.gitignore index 9e2f00343f15..90c238ba6a4b 100644 --- a/tools/testing/selftests/exec/.gitignore +++ b/tools/testing/selftests/exec/.gitignore @@ -7,6 +7,8 @@ execveat.moved execveat.path.ephemeral execveat.ephemeral execveat.denatured +non-regular +null-argv /load_address_* /recursion-depth xxxxxxxx* -- cgit