core: let selinux_setup() load policy more than once
When you switch-root into a new root that has SELinux policy, you're
supposed to to run selinux_init_load_policy() to set up SELinux and load
policy. Normally this gets handled by selinux_setup().
But if SELinux was already initialized, selinux_setup() skips loading
policy and returns 0. So if you load policy normally, and then you
switch-root to a new root that has new policy, selinux_setup() never
loads the new policy. What gives?
As far as I can tell, this check is an artifact of how selinux_setup()
worked when it was first written (see commit c4dcdb9
/ systemd v12):
* when systemd starts, run selinux_setup()
* if selinux_setup() loads policy OK, restart systemd
So the "if policy already loaded, skip load and return 0" check was
there to prevent an infinite re-exec loop.
Modern systemd only calls selinux_setup() on initial load and after
switch-root, and selinux_setup() no longer restarts systemd, so we don't
need that check to guard against the infinite loop anymore.
So: this patch removes the "return 0", thus allowing selinux_setup() to
actually perform SELinux setup after switch-root.
We still want to check to see if SELinux is initialized, because if
selinux_init_load_policy() fails *but* SELinux is initialized that means
we still have (old) policy active. So we don't need to halt if
enforce=1.
This commit is contained in:
parent
d36d90933a
commit
68d3acaccb
|
@ -51,6 +51,7 @@ int selinux_setup(bool *loaded_policy) {
|
|||
security_context_t con;
|
||||
int r;
|
||||
union selinux_callback cb;
|
||||
bool initialized = false;
|
||||
|
||||
assert(loaded_policy);
|
||||
|
||||
|
@ -68,13 +69,8 @@ int selinux_setup(bool *loaded_policy) {
|
|||
/* Already initialized by somebody else? */
|
||||
r = getcon_raw(&con);
|
||||
if (r == 0) {
|
||||
bool initialized;
|
||||
|
||||
initialized = !streq(con, "kernel");
|
||||
freecon(con);
|
||||
|
||||
if (initialized)
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Make sure we have no fds open while loading the policy and
|
||||
|
@ -116,8 +112,12 @@ int selinux_setup(bool *loaded_policy) {
|
|||
log_open();
|
||||
|
||||
if (enforce > 0) {
|
||||
log_error("Failed to load SELinux policy. Freezing.");
|
||||
return -EIO;
|
||||
if (!initialized) {
|
||||
log_error("Failed to load SELinux policy. Freezing.");
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
log_warning("Failed to load new SELinux policy. Continuing with old policy.");
|
||||
} else
|
||||
log_debug("Unable to load SELinux policy. Ignoring.");
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue