NetBSD Problem Report #53367

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Date: Fri, 15 Jun 2018 15:01:25 +0000 (UTC)
From: thomas.barabosch@fkie.fraunhofer.de
Reply-To: thomas.barabosch@fkie.fraunhofer.de
To: gnats-bugs@NetBSD.org
Subject: Integer overflow in usr.sbin/dumplfs
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>Number:         53367
>Category:       bin
>Synopsis:       Integer overflow in usr.sbin/dumplfs
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    bin-bug-people
>State:          closed
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Jun 15 15:05:00 +0000 2018
>Closed-Date:    Sat Jun 16 23:57:15 +0000 2018
>Last-Modified:  Sat Jun 16 23:57:15 +0000 2018
>Originator:     Thomas Barabosch
>Release:        7.1.2
>Organization:
Fraunhofer FKIE
>Environment:
>Description:
There is a memory allocation in usr.sbin/dumplfs/dumplfs.c with malloc that utilizes multiplication. This is considered harmful and it is better to utilize calloc. Furthermore, there is a possible null pointer reference since malloc may fail to allocate memory but there is no check for a NULL return value.

I've drafted a patch as a possible solution to this issue.
>How-To-Repeat:

>Fix:
--- usr.sbin/dumplfs/dumplfs.c	2018-05-14 00:00:49.651718558 +0200
+++ usr.sbin/dumplfs/dumplfs.c.patched	2018-06-15 16:54:43.556979202 +0200
@@ -680,8 +680,8 @@
 	} else {
 		el_size = sizeof(u_int32_t);
 	}
-	datap = (char *)malloc(el_size * numblocks);
-	memset(datap, 0, el_size * numblocks);
+	if ((datap = (char *)calloc(numblocks, el_size)) == NULL)
+            err(1, "calloc");
 	acc = 0;
 	addr += lfs_btofsb(lfsp, lfs_sb_getsumsize(lfsp));
 	buf = malloc(lfs_sb_getbsize(lfsp));

>Release-Note:

>Audit-Trail:
From: "Christos Zoulas" <christos@netbsd.org>
To: gnats-bugs@gnats.NetBSD.org
Cc: 
Subject: PR/53367 CVS commit: src/usr.sbin/dumplfs
Date: Fri, 15 Jun 2018 11:16:05 -0400

 Module Name:	src
 Committed By:	christos
 Date:		Fri Jun 15 15:16:05 UTC 2018

 Modified Files:
 	src/usr.sbin/dumplfs: Makefile dumplfs.c

 Log Message:
 PR/53367: Thomas Barabosch: Integer overflow in usr.sbin/dumplfs
 While here use the "e" functions to always check for allocation errors.


 To generate a diff of this commit:
 cvs rdiff -u -r1.17 -r1.18 src/usr.sbin/dumplfs/Makefile
 cvs rdiff -u -r1.63 -r1.64 src/usr.sbin/dumplfs/dumplfs.c

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

State-Changed-From-To: open->closed
State-Changed-By: dholland@NetBSD.org
State-Changed-When: Sat, 16 Jun 2018 23:57:15 +0000
State-Changed-Why:
fixed


>Unformatted:

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