svn commit: r360973 - in stable: 11/sys/netinet/libalias 12/sys/netinet/libalias

[Ed Maste]

Author: emaste
Date: Tue May 12 16:52:08 2020
New Revision: 360973
URL: https://svnweb.freebsd.org/changeset/base/360973

Log:
  MFC r360968: libalias: fix potential memory disclosure from ftp module
  
  admbugs:	956
  Submitted by:	markj
  Reported by:	Vishnu Dev TJ working with Trend Micro Zero Day Initiative
  Approved by:	so
  Security:	FreeBSD-SA-20:13.libalias
  Security:	CVE-2020-7455
  Security:	ZDI-CAN-10849

Modified:
  stable/12/sys/netinet/libalias/alias_ftp.c
Directory Properties:
  stable/12/   (props changed)

Changes in other areas also in this revision:
Modified:
  stable/11/sys/netinet/libalias/alias_ftp.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/12/sys/netinet/libalias/alias_ftp.c
==============================================================================
--- stable/12/sys/netinet/libalias/alias_ftp.c	Tue May 12 16:51:11 2020	(r360972)
+++ stable/12/sys/netinet/libalias/alias_ftp.c	Tue May 12 16:52:08 2020	(r360973)
@@ -754,7 +754,8 @@ NewFtpMessage(struct libalias *la, struct ip *pip,
 		{
 			u_short new_len;
 
-			new_len = htons(hlen + slen);
+			new_len = htons(hlen +
+			    MIN(slen, maxpacketsize - hlen));
 			DifferentialChecksum(&pip->ip_sum,
 			    &new_len,
 			    &pip->ip_len,