Patch-ID# 100149-03
Keywords: panic mclput mbuf IP packet drops packets
Synopsis: SunOS 4.1 and 4.1.1: system crashes with mclput panic
Date: 07-April-91

SunOS release: 4.1 4.1.1

Topic: kernel panic mclput

BugID's fixed with this patch: 1041559 1053552

Architectures for which this patch is available: sun3 sun3x sun4 sun4c

Problem description:

Bug ID: 1041559
Certain sequence of IP packets cause the mbuf chain to
be corrupted resulting in the above panic.

Bug ID: 1053552
kernels with mclput panic patch installed (ip_input.o) 
PatchID 100149-01 will drop IP packets which have any IP
options included in the packet. Problem being incorrect 
checksum for packets with IP-header length > 20 bytes

Fix description:

The fix includes patched version of:

ip_input.o

INSTALL:

as root
the appopriate sun3 sun3x sun4 or sun4c patches as follows:

# mv /sys/sun{3,3x,4,4c}/OBJ/ip_input.o /sys/sun{3,3x,4,4c}/OBJ/ip_input.o.FCS
# cp sun{3,3x,4,4c}/ip_input.o /sys/sun{3,3x,4,4c}/OBJ/ip_input.o
# chmod 444 /sys/sun{3,3x,4,4c}/OBJ/ip_input.o
 
 A new kernel will need to be configured and built.
 Please refer to the "System and Network Administration" portion
 of the manual for building and installing a custom kernel.