ladybird/Userland/chown.cpp
Andreas Kling 040ba77d44 Userland: Fix null-pointer deref on unknown user/group in chown/chgrp
We can't just blindly dereference the result of getpwnam()/getgrnam()!

Fixes #1625.
2020-04-04 19:29:30 +02:00

87 lines
2.7 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/String.h>
#include <AK/Vector.h>
#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
int main(int argc, char** argv)
{
if (pledge("stdio rpath chown", nullptr) < 0) {
perror("pledge");
return 1;
}
if (argc < 3) {
printf("usage: chown <uid[:gid]> <path>\n");
return 0;
}
uid_t new_uid = -1;
gid_t new_gid = -1;
auto parts = String(argv[1]).split(':');
if (parts.is_empty()) {
fprintf(stderr, "Empty uid/gid spec\n");
return 1;
}
bool ok;
new_uid = parts[0].to_uint(ok);
if (!ok) {
auto* passwd = getpwnam(parts[0].characters());
if (!passwd) {
fprintf(stderr, "Unknown user '%s'\n", parts[0].characters());
return 1;
}
new_uid = passwd->pw_uid;
}
if (parts.size() == 2) {
new_gid = parts[1].to_uint(ok);
if (!ok) {
auto* group = getgrnam(parts[1].characters());
if (!new_gid) {
fprintf(stderr, "Unknown group '%s'\n", parts[1].characters());
return 1;
}
new_gid = group->gr_gid;
}
}
int rc = chown(argv[2], new_uid, new_gid);
if (rc < 0) {
perror("chown");
return 1;
}
return 0;
}