CVS commit: src/sys/netinet

["Maxime Villard" <maxv%netbsd.org@localhost>]

Module Name:    src
Committed By:   maxv
Date:           Sun Apr  1 12:58:47 UTC 2018

Modified Files:
        src/sys/netinet: tcp_output.c

Log Message:
Change the check to be <= instead of <. This fixes one occurrence of an
apparently widespread division-by-zero bug in our TCP code: if a user adds
huge IPv6 options with setsockopt, and if the total size of the options
happens to be equal to the available space calculated for the TCP payload,
t_segsz gets set to zero, and given that we then divide several things by
it, the kernel crashes.


To generate a diff of this commit:
cvs rdiff -u -r1.203 -r1.204 src/sys/netinet/tcp_output.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.