linux-kernel - Re: BUG: mmapfile/writev spurious zero bytes (x86

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <alpine.LFD.1.10.0806171421100.2907@woody.linux-foundation.org>
Date:	Tue, 17 Jun 2008 14:24:39 -0700 (PDT)
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Andi Kleen <andi@...stfloor.org>
cc:	Bron Gondwana <brong@...tmail.fm>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Nick Piggin <npiggin@...e.de>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Rob Mueller <robm@...tmail.fm>, Ingo Molnar <mingo@...e.hu>
Subject: Re: BUG: mmapfile/writev spurious zero bytes (x86_64/not i386,
 bisected, reproducable)

On Tue, 17 Jun 2008, Andi Kleen wrote:
> 
> If that fixes anything:
> - The caller is broken because it shouldn't pass a faulting source to copy_to_user()
> - And you broken copy_from_user error reporting which shares the same code

Andi, I'm sorry I cc'd you. You are the author of that crap, but the bug 
seems to be that you never even understood what copy_from_user() is 
supposed to do.

The whole *and*only* reason for copy_to/from_user() existing AT ALL is 
exactly the fact that the source or destination access can fault. 

I don't really see why you continually start arguing about things that are 
OBVIOUSLY BUGGY, as if they weren't buggy. Once somebody has debugged a 
buggy routine, you shouldn't argue against it. 

So here's a hint: next time I claim some code of yours is buggy, either 
just acknowledge the bug, or stay silent. You'll look smarter that way.

			Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/