e14ea3f5c3
When glusterfs wants to retrieve the list of auxiliary gids of a user, it typically allocates a sufficiently big gid_t array on stack and calls getgrouplist(3) with it. However, "sufficiently big" means to be of maximum supported gid list size, which in GlusterFS is GF_MAX_AUX_GROUPS = 64k. That means a 64k * sizeof(gid_t) = 256k allocation, which is big enough to overflow the stack in certain cases. A further observation is that stack allocation of the gid list brings no gain, as in all cases the content of the gid list eventually gets copied over to a heap allocated buffer. So we add a convenience wrapper of getgrouplist to libglusterfs called gf_getgrouplist which calls getgrouplist with a sufficiently big heap allocated buffer (it takes care of the allocation too). We are porting all the getgrouplist invocations to gf_getgrouplist and thus eliminate the huge stack allocation. BUG: 1464327 Change-Id: Icea76d0d74dcf2f87d26cb299acc771ca3b32d2b Signed-off-by: Csaba Henk <csaba@redhat.com> Reviewed-on: https://review.gluster.org/17706 Smoke: Gluster Build System <jenkins@build.gluster.org> Reviewed-by: Niels de Vos <ndevos@redhat.com> Reviewed-by: Amar Tumballi <amarts@redhat.com> CentOS-regression: Gluster Build System <jenkins@build.gluster.org>