NetBSD Problem Report #54594

From martin@duskware.de  Wed Oct  2 15:08:58 2019
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From: martin@NetBSD.org
Reply-To: martin@NetBSD.org
To: gnats-bugs@NetBSD.org
Subject: bind may crash at startup
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>Number:         54594
>Category:       bin
>Synopsis:       bind may crash at startup
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    bin-bug-people
>State:          closed
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Oct 02 15:10:00 +0000 2019
>Closed-Date:    Wed Nov 13 18:05:11 +0000 2019
>Last-Modified:  Wed Nov 13 18:05:11 +0000 2019
>Originator:     Martin Husemann
>Release:        NetBSD 9.99.15
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD unpluged.duskware.de 9.99.15 NetBSD 9.99.15 (UNPLUGED) #266: Wed Oct 2 12:14:19 CEST 2019 martin@seven-days-to-the-wolves.aprisoft.de:/work/src/sys/arch/evbarm/compile/UNPLUGED evbarm
Architecture: earm
Machine: evbarm
>Description:

On alignement critical architectures, bind may crash at startup when it 
initializes its internal keys.

In dist/lib/isc/hash.c:39 there is a global storage for a key:

static uint8_t isc_hash_key[16];

which is initialized in line 141:

                isc_siphash24(isc_hash_key, input, length, (uint8_t *)&hval);

but isc_siphash24 expects the key to be properly aligned for a 64bit
value:

void
isc_siphash24(const uint8_t *k, const uint8_t *in, size_t inlen, uint8_t *out)
{
        const uint64_t *key = (const uint64_t *)k;

And depending on how linking ends up for that byte array, we loose or win.
Example crash:

Core was generated by `named'.
Program terminated with signal SIGBUS, Bus error.
#0  isc_siphash24 (
    k=0xbbbc71f4 "\365q\036\362\255\214tLC\226XxO\230\346\251\001", 
    in=in@entry=0xbfffd6e0 "", inlen=inlen@entry=1, 
    out=out@entry=0xbfffd6d8 "")
(gdb) up
#1  0xbbba0ad4 in isc_hash_function (data=0xbb2579f8, length=1, 
    case_sensitive=<optimized out>)
    at /work/src/external/mpl/bind/lib/libisc/../../dist/lib/isc/hash.c:141
141     /work/src/external/mpl/bind/lib/libisc/../../dist/lib/isc/hash.c: No such file or directory.


>How-To-Repeat:
n/a

>Fix:
Add alignment attributes to the isc_hash_key? Make it a union with uint64_t?

>Release-Note:

>Audit-Trail:
From: "Christos Zoulas" <christos@netbsd.org>
To: gnats-bugs@gnats.NetBSD.org
Cc: 
Subject: PR/54594 CVS commit: src/external/mpl/bind/dist/lib/isc
Date: Wed, 2 Oct 2019 11:43:15 -0400

 Module Name:	src
 Committed By:	christos
 Date:		Wed Oct  2 15:43:15 UTC 2019

 Modified Files:
 	src/external/mpl/bind/dist/lib/isc: siphash.c

 Log Message:
 PR/54594: Martin Husemann: bind may crash at startup
 Use memcpy(3) instead of assuming casting "uint8_t *" to "uint64_t *" and
 de-referencing works.


 To generate a diff of this commit:
 cvs rdiff -u -r1.2 -r1.3 src/external/mpl/bind/dist/lib/isc/siphash.c

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

From: "Martin Husemann" <martin@netbsd.org>
To: gnats-bugs@gnats.NetBSD.org
Cc: 
Subject: PR/54594 CVS commit: [netbsd-9] src/external/mpl/bind/dist/lib/isc
Date: Thu, 3 Oct 2019 17:31:02 +0000

 Module Name:	src
 Committed By:	martin
 Date:		Thu Oct  3 17:31:02 UTC 2019

 Modified Files:
 	src/external/mpl/bind/dist/lib/isc [netbsd-9]: siphash.c

 Log Message:
 Pull up following revision(s) (requested by christos in ticket #279):

 	external/mpl/bind/dist/lib/isc/siphash.c: revision 1.3

 PR/54594: Martin Husemann: bind may crash at startup

 Use memcpy(3) instead of assuming casting "uint8_t *" to "uint64_t *" and
 de-referencing works.


 To generate a diff of this commit:
 cvs rdiff -u -r1.2.2.2 -r1.2.2.3 src/external/mpl/bind/dist/lib/isc/siphash.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: martin@NetBSD.org
State-Changed-When: Wed, 13 Nov 2019 18:05:11 +0000
State-Changed-Why:
Christos fixed it


>Unformatted:

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