mirror of
https://passt.top/passt
synced 2025-06-08 08:35:35 +02:00
conf: Add --runas option, changing to given UID and GID if started as root
On some systems, user and group "nobody" might not be available. The new --runas option allows to override the default "nobody" choice if started as root. Now that we allow this, drop the initgroups() call that was used to add any additional groups for the given user, as that might now grant unnecessarily broad permissions. For instance, several distributions have a "kvm" group to allow regular user access to /dev/kvm, and we don't need that in passt or pasta. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
parent
c318ffcb4c
commit
a951e0b9ef
6 changed files with 135 additions and 46 deletions
46
passt.c
46
passt.c
|
@ -46,8 +46,6 @@
|
|||
#include <sys/stat.h>
|
||||
#include <sys/prctl.h>
|
||||
#include <stddef.h>
|
||||
#include <pwd.h>
|
||||
#include <grp.h>
|
||||
#include <netinet/udp.h>
|
||||
#include <netinet/tcp.h>
|
||||
#include <netinet/if_ether.h>
|
||||
|
@ -190,49 +188,6 @@ static void seccomp(const struct ctx *c)
|
|||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* check_root() - Warn if root in init, exit if we can't drop to nobody
|
||||
*/
|
||||
static void check_root(void)
|
||||
{
|
||||
const char root_uid_map[] = " 0 0 4294967295";
|
||||
struct passwd *pw;
|
||||
char buf[BUFSIZ];
|
||||
int fd;
|
||||
|
||||
if (getuid() && geteuid())
|
||||
return;
|
||||
|
||||
if ((fd = open("/proc/self/uid_map", O_RDONLY | O_CLOEXEC)) < 0)
|
||||
return;
|
||||
|
||||
if (read(fd, buf, BUFSIZ) != sizeof(root_uid_map) ||
|
||||
strncmp(buf, root_uid_map, sizeof(root_uid_map) - 1)) {
|
||||
close(fd);
|
||||
return;
|
||||
}
|
||||
|
||||
close(fd);
|
||||
|
||||
fprintf(stderr, "Don't run this as root. Changing to nobody...\n");
|
||||
#ifndef GLIBC_NO_STATIC_NSS
|
||||
pw = getpwnam("nobody");
|
||||
if (!pw) {
|
||||
perror("getpwnam");
|
||||
exit(EXIT_FAILURE);
|
||||
}
|
||||
|
||||
if (!initgroups(pw->pw_name, pw->pw_gid) &&
|
||||
!setgid(pw->pw_gid) && !setuid(pw->pw_uid))
|
||||
return;
|
||||
#else
|
||||
(void)pw;
|
||||
#endif
|
||||
|
||||
fprintf(stderr, "Can't change to user/group nobody, exiting");
|
||||
exit(EXIT_FAILURE);
|
||||
}
|
||||
|
||||
/**
|
||||
* sandbox() - Unshare IPC, mount, PID, UTS, and user namespaces, "unmount" root
|
||||
*
|
||||
|
@ -336,7 +291,6 @@ int main(int argc, char **argv)
|
|||
|
||||
arch_avx2_exec(argv);
|
||||
|
||||
check_root();
|
||||
drop_caps();
|
||||
|
||||
c.pasta_userns_fd = c.pasta_netns_fd = c.fd_tap = c.fd_tap_listen = -1;
|
||||
|
|
Loading…
Add table
Add a link
Reference in a new issue