CVS commit: src/sys/netinet

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

Module Name:    src
Committed By:   maxv
Date:           Fri May 15 06:34:34 UTC 2020

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

Log Message:
igmp_sendpkt() expects ip_output() to set 'imo.imo_multicast_ttl' into
'ip->ip_ttl'; but ip_output() won't if the target is not a multicast
address, meaning that the uninitialized 'ip->ip_ttl' byte gets sent to
the network. This leaks one byte of kernel heap.

Fix this by filling 'ip->ip_ttl' with a TTL of one.

Found by KMSAN.

Reported-by: syzbot+e49f7b8a8fec5a477c9a%syzkaller.appspotmail.com@localhost


To generate a diff of this commit:
cvs rdiff -u -r1.69 -r1.70 src/sys/netinet/igmp.c

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