Hi Petr, thanks for reviewing and fixing this!
On Wed, Jan 15, 2020 at 11:30:57AM +0100, Petr Štetiar wrote: > Commit a5af33ce9a16 ("instance: strdup string attributes") has > introduced duplication of various string attributes in order to fix > use-after-free, but missed handling of one `pidfile` attribute case in > instance_config_move() where the new value of `pidfile` is being > copied/assigned. Source of this value is then free()d in following 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 Right, didn't think about that. I don't have time to get into this right now (but will have tonight or tomorrow), but doesn't the same also apply at least for the 'seccomp' field? Cheers Daniel > > Ref: FS#2723 > Cc: Daniel Golle <dan...@makrotopia.org> > Fixes: a5af33ce9a16 ("instance: strdup string attributes") > Signed-off-by: Petr Štetiar <yn...@true.cz> > --- > service/instance.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/service/instance.c b/service/instance.c > index ce5233807dbb..245b9629d99a 100644 > --- a/service/instance.c > +++ b/service/instance.c > @@ -1031,7 +1031,6 @@ 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; > @@ -1042,6 +1041,10 @@ instance_config_move(struct service_instance *in, > struct service_instance *in_sr > in->node.avl.key = in_src->node.avl.key; > in->syslog_facility = in_src->syslog_facility; > > + free(in->pidfile); > + if (in_src->pidfile) > + in->pidfile = strdup(in_src->pidfile); > + > free(in->config); > in->config = in_src->config; > in_src->config = NULL; _______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel