NLMSG_NEXT decrements the buffer length (status) by
the header msg length (nlmsg_len) everytime its called.
If nlmsg_len isn't accurate and set to be larger than
what it should represent, it will cause status to
decrement passed 0. This makes NLMSG_NEXT return a
pointer that references an inaccessible address.
When that is passed to NLMSG_OK, it segfaults.
Add a check to verify that there is still something to read
before we try to.
Signed-off-by: Stephen Worley <sworley@cumulusnetworks.com>
FRRouting is free software that implements and manages various IPv4 and IPv6
routing protocols.
Currently FRRouting supports BGP4, BGP4+, OSPFv2, OSPFv3, RIPv1, RIPv2, RIPng,
IS-IS, PIM-SM/MSDP, LDP and Babel as well as very early support for EIGRP and
NHRP.
See doc/user/bugs.rst for information on how to report bugs.
See doc/developer/workflow.rst for information on contributing.
See the file COPYING for copying conditions.
Public email discussion can be found at https://lists.frrouting.org/listinfo
Our public slack channel is at https://frrouting.slack.com