@@ -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;
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 <daniel@makrotopia.org> Signed-off-by: Petr Štetiar <ynezz@true.cz> --- changes since v3: * prevent double free, again * follow DRY and use instance_config_move_strdup service/instance.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-)