cb86eba3ab was causing zebra to crash
when handling a nexthop group that had a nexthop which was recursively resolved.
Steps to recreate:
!
nexthop-group red
nexthop 1.1.1.1
nexthop 1.1.1.2
!
sharp install routes 8.8.8.1 nexthop-group red 1
=========================================
==11898== Invalid write of size 8
==11898== at 0x48E53B4: _nexthop_add_sorted (nexthop_group.c:254)
==11898== by 0x48E5336: nexthop_group_add_sorted (nexthop_group.c:296)
==11898== by 0x453593: handle_recursive_depend (zebra_nhg.c:481)
==11898== by 0x451CA8: zebra_nhg_find (zebra_nhg.c:572)
==11898== by 0x4530FB: zebra_nhg_find_nexthop (zebra_nhg.c:597)
==11898== by 0x4536B4: depends_find (zebra_nhg.c:1065)
==11898== by 0x453526: depends_find_add (zebra_nhg.c:1087)
==11898== by 0x451C4D: zebra_nhg_find (zebra_nhg.c:567)
==11898== by 0x4519DE: zebra_nhg_rib_find (zebra_nhg.c:1126)
==11898== by 0x452268: nexthop_active_update (zebra_nhg.c:1729)
==11898== by 0x461517: rib_process (zebra_rib.c:1049)
==11898== by 0x4610C8: process_subq_route (zebra_rib.c:1967)
==11898== Address 0x0 is not stack'd, malloc'd or (recently) free'd
Zebra crashes because we weren't handling the case of the depend nexthop
being recursive.
For this case, we cannot make the function more efficient. A nexthop
could resolve to a group of any size, thus we need allocs/frees.
To solve this and retain the goal of the original patch, we separate out the
two cases so it will still be more efficient if the nexthop is not recursive.
Signed-off-by: Stephen Worley <sworley@cumulusnetworks.com>
FRR is free software that implements and manages various IPv4 and IPv6 routing
protocols. It runs on nearly all distributions of Linux and BSD as well as
Solaris and supports all modern CPU architectures.
For chat, we currently use Slack. You can join
by clicking the "Slack" link under the
Participate section of our website.
Contributing
FRR maintains developer's documentation
which contains the project workflow
and expectations for contributors. Some technical documentation on project
internals is also available.
We welcome and appreciate all contributions, no matter how small!
Security
To report security issues, please use our security mailing list: