idmap: always seteuid to the owner of the namespace

simplify the condition for setting the euid of the process.  Now it is
always set when we are running as root, the issue was introduced with
the commit 52c081b02c

Changelog: 2018-11-24 - seh - enforce that euid only gets set to ruid if
   it currently == 0 (i.e. really was setuid-*root*).

Closes: https://github.com/genuinetools/img/issues/191

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
Signed-off-by: Serge Hallyn <shallyn@cisco.com>
This commit is contained in:
Giuseppe Scrivano 2018-11-20 20:43:43 +01:00 committed by Serge Hallyn
parent 42324e5017
commit 59c2dabb26

View File

@ -161,14 +161,8 @@ void write_mapping(int proc_dir_fd, int ranges, struct map_range *mappings,
exit(EXIT_FAILURE);
}
if (capget(&hdr, data) < 0) {
fprintf(stderr, _("%s: Could not get capabilities\n"), Prog);
exit(EXIT_FAILURE);
}
/* Align setuid- and fscaps-based new{g,u}idmap behavior. */
if (!(data[0].effective & CAP_TO_MASK(CAP_SYS_ADMIN)) && ruid != 0 &&
ruid == getuid() && ruid != geteuid()) {
if (geteuid() == 0 && geteuid() != ruid) {
if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) < 0) {
fprintf(stderr, _("%s: Could not prctl(PR_SET_KEEPCAPS)\n"), Prog);
exit(EXIT_FAILURE);