diff --git a/lib/libjail/jail_getid.c b/lib/libjail/jail_getid.c index f99a175fd398..3700ff0d36cc 100644 --- a/lib/libjail/jail_getid.c +++ b/lib/libjail/jail_getid.c @@ -54,6 +54,15 @@ jail_getid(const char *name) jid = strtoul(name, &ep, 10); if (*name && !*ep) { + /* + * jid == 0 is a special case; it will not appear in the + * kernel's jail list, but naturally processes will be assigned + * to it because it is prison 0. Trivially return this one + * without a trip to the kernel, because it always exists but + * the lookup won't succeed. + */ + if (jid == 0) + return jid; jiov[0].iov_base = __DECONST(char *, "jid"); jiov[0].iov_len = sizeof("jid"); jiov[1].iov_base = &jid;