netdev - Re: authenc compile warnings in current net-2.6.24

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 10 Oct 2007 16:25:28 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	netdev@...breakpoint.cc
Cc:	socketcan@...tkopp.net, herbert@...dor.apana.org.au,
	netdev@...r.kernel.org
Subject: Re: authenc compile warnings in current net-2.6.24

From: Sebastian Siewior <netdev@...breakpoint.cc>
Date: Wed, 10 Oct 2007 21:53:37 +0200

> * Oliver Hartkopp | 2007-10-10 19:53:53 [+0200]:
> 
> > CC [M] crypto/authenc.o
> > crypto/authenc.c: In function ?crypto_authenc_hash?:
> > crypto/authenc.c:88: warning: ?cryptlen? may be used uninitialized in this 
> > function
> > crypto/authenc.c:87: warning: ?dst? may be used uninitialized in this 
> > function
> > crypto/authenc.c: In function ?crypto_authenc_decrypt?:
> > crypto/authenc.c:163: warning: ?cryptlen? may be used uninitialized in this 
> > function
> > crypto/authenc.c:163: note: ?cryptlen? was declared here
> > crypto/authenc.c:162: warning: ?src? may be used uninitialized in this 
> > function
> > crypto/authenc.c:162: note: ?src? was declared here
> >
> > do you already know these warnings?
> 
> Those warnings are looking like a compiler bug to me.

It's just not smart enough to see that cryptlen's initialization
and it's use in the auth_unlock label path are both protected
by 'err' being non-zero.

To be honest I don't know of any compiler which commits enough
flow variable analysis to support doing %100 accurate warnings
in situations like this.

Since the compiler is unlikely to do so, I think we should fix
it somehow because useless warnings just distract.
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html