nspawn: Allow module loading if CAP_SYS_MODULE is requested

nspawn containers currently block module loading in all cases, with
no option to disable it. This allows an admin, specifically setting
capability=CAP_SYS_MODULE or capability=all to load modules.
This commit is contained in:
Jay Faulkner 2015-02-03 17:45:50 -08:00 committed by Lennart Poettering
parent 057255fbbf
commit d0a0ccf3fe

View file

@ -2485,15 +2485,18 @@ static int setup_seccomp(void) {
static const int blacklist[] = {
SCMP_SYS(kexec_load),
SCMP_SYS(open_by_handle_at),
SCMP_SYS(init_module),
SCMP_SYS(finit_module),
SCMP_SYS(delete_module),
SCMP_SYS(iopl),
SCMP_SYS(ioperm),
SCMP_SYS(swapon),
SCMP_SYS(swapoff),
};
static const int kmod_blacklist[] = {
SCMP_SYS(init_module),
SCMP_SYS(finit_module),
SCMP_SYS(delete_module),
};
scmp_filter_ctx seccomp;
unsigned i;
int r;
@ -2518,6 +2521,20 @@ static int setup_seccomp(void) {
}
}
/* If the CAP_SYS_MODULE capability is not requested then
* we'll block the kmod syscalls too */
if (!(arg_retain & (1ULL << CAP_SYS_MODULE))) {
for (i = 0; i < ELEMENTSOF(kmod_blacklist); i++) {
r = seccomp_rule_add(seccomp, SCMP_ACT_ERRNO(EPERM), kmod_blacklist[i], 0);
if (r == -EFAULT)
continue; /* unknown syscall */
if (r < 0) {
log_error_errno(r, "Failed to block syscall: %m");
goto finish;
}
}
}
/*
Audit is broken in containers, much of the userspace audit
hookup will fail if running inside a container. We don't