From 153820c764719adfbcb185d35e63587097ddecbe Mon Sep 17 00:00:00 2001 From: =?utf8?q?Petr=20=C5=A0tetiar?= Date: Fri, 17 Jan 2020 18:22:37 +0100 Subject: [PATCH] instance: fix pidfile and seccomp attributes double free MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Commit a5af33ce9a16 ("instance: strdup string attributes") has introduced duplication of various string attributes in order to fix use-after-free, but missed handling of `pidfile` and `seccomp` attribute cases in instance_config_move() where the new value of `pidfile` or `seccomp` is being copied/assigned. Source of this values is then free()d in subsequent call to instance_free() and then again for 2nd time during the service stop command handling, leading to double free crash: #0 unmap_chunk at src/malloc/malloc.c:515 #1 free at src/malloc/malloc.c:526 #2 instance_free (in=0xd5e300) at instance.c:1100 #3 instance_delete (in=0xd5e300) at instance.c:559 #4 instance_stop (in=0xd5e300, halt=true) at instance.c:611 While at it, add missing handling of jail.name and jail.hostname attributes as well. Ref: FS#2723 Fixes: a5af33ce9a16 ("instance: strdup string attributes") Signed-off-by: Daniel Golle Signed-off-by: Petr Å tetiar --- service/instance.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/service/instance.c b/service/instance.c index b0c9807..342199a 100644 --- a/service/instance.c +++ b/service/instance.c @@ -1018,6 +1018,21 @@ instance_config_cleanup(struct service_instance *in) blobmsg_list_free(&in->jail.mount); } +static void +instance_config_move_strdup(char **dst, char *src) +{ + if (!*dst) + return; + + free(*dst); + *dst = NULL; + + if (!src) + return; + + *dst = strdup(src); +} + static void instance_config_move(struct service_instance *in, struct service_instance *in_src) { @@ -1031,17 +1046,20 @@ instance_config_move(struct service_instance *in, struct service_instance *in_sr blobmsg_list_move(&in->jail.mount, &in_src->jail.mount); in->trigger = in_src->trigger; in->command = in_src->command; - in->pidfile = in_src->pidfile; in->respawn = in_src->respawn; in->respawn_retry = in_src->respawn_retry; in->respawn_threshold = in_src->respawn_threshold; in->respawn_timeout = in_src->respawn_timeout; in->name = in_src->name; in->trace = in_src->trace; - in->seccomp = in_src->seccomp; in->node.avl.key = in_src->node.avl.key; in->syslog_facility = in_src->syslog_facility; + instance_config_move_strdup(&in->pidfile, in_src->pidfile); + instance_config_move_strdup(&in->seccomp, in_src->seccomp); + instance_config_move_strdup(&in->jail.name, in_src->jail.name); + instance_config_move_strdup(&in->jail.hostname, in_src->jail.hostname); + free(in->config); in->config = in_src->config; in_src->config = NULL; -- 2.25.1