From 64bb8a3881aab0c9fecd7c3dceeea2e89e146e0e Mon Sep 17 00:00:00 2001 From: Hiroki Sato Date: Wed, 8 Jul 2015 16:37:48 +0000 Subject: [PATCH] Implement PF_IMMUTABLE flag and apply it to "name" and "jid" in jail.conf parameters. This flag disallows redefinition of the parameter. "name" and/or "jid" are automatically defined in jail.conf by using the jail names at the front of jail parameter definitions. However, one could override them by using a variable with the same name like $name = "foo". This confused the parser and could end up with SIGSEGV. Note that this change also affects a case when all of parameters are defined in the command line arguments, not in jail.conf. Specifically, "jail -c name=j1 name=j2" no longer works. This should be harmless. PR: 196574 Reviewed by: jamie Differential Revision: https://reviews.freebsd.org/D3017 --- usr.sbin/jail/config.c | 9 +++++++-- usr.sbin/jail/jailp.h | 1 + 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/usr.sbin/jail/config.c b/usr.sbin/jail/config.c index 1dd04498bcd..87b8ef9675a 100644 --- a/usr.sbin/jail/config.c +++ b/usr.sbin/jail/config.c @@ -111,8 +111,8 @@ static const struct ipspec intparams[] = { #ifdef INET6 [KP_IP6_ADDR] = {"ip6.addr", 0}, #endif - [KP_JID] = {"jid", 0}, - [KP_NAME] = {"name", 0}, + [KP_JID] = {"jid", PF_IMMUTABLE}, + [KP_NAME] = {"name", PF_IMMUTABLE}, [KP_PATH] = {"path", 0}, [KP_PERSIST] = {"persist", 0}, [KP_SECURELEVEL] = {"securelevel", 0}, @@ -362,6 +362,11 @@ add_param(struct cfjail *j, const struct cfparam *p, enum intparam ipnum, break; if (dp != NULL) { /* Found it - append or replace. */ + if (dp->flags & PF_IMMUTABLE) { + jail_warnx(j, "cannot redefine variable \"%s\".", + dp->name); + return; + } if (strcmp(dp->name, name)) { free(dp->name); dp->name = estrdup(name); diff --git a/usr.sbin/jail/jailp.h b/usr.sbin/jail/jailp.h index bfefca56c10..d2c929e32f0 100644 --- a/usr.sbin/jail/jailp.h +++ b/usr.sbin/jail/jailp.h @@ -51,6 +51,7 @@ #define PF_INT 0x20 /* Integer parameter */ #define PF_CONV 0x40 /* Parameter duplicated in converted form */ #define PF_REV 0x80 /* Run commands in reverse order on stopping */ +#define PF_IMMUTABLE 0x100 /* Immutable parameter */ #define JF_START 0x0001 /* -c */ #define JF_SET 0x0002 /* -m */