linux-kernel - RE: [PATCH][v2] proc: use vmalloc for our kernel buffer

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: <3612878ce143427b89a70de3abfb657d@AcuMS.aculab.com>
Date:   Thu, 13 Aug 2020 21:10:43 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     'Josef Bacik' <josef@...icpanda.com>,
        Al Viro <viro@...iv.linux.org.uk>,
        Christoph Hellwig <hch@....de>
CC:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
        "kernel-team@...com" <kernel-team@...com>,
        "willy@...radead.org" <willy@...radead.org>
Subject: RE: [PATCH][v2] proc: use vmalloc for our kernel buffer

From: Josef Bacik
> Sent: 13 August 2020 18:19
...
> We wouldn't even need the extra +1 part, since we're only copying in how much
> the user wants anyway, we could just go ahead and convert this to
> 
> left -= snprintf(buffer, left, "0x%04x\n", *(unsigned int *) table->data);
> 
> and be fine, right?  Or am I misunderstanding what you're looking for?  Thanks,

Doesn't that need to be scnprintf()?
IIRC snprintf() returns the number of bytes that would have been
written were the buffer infinite size?
(I suspect this is an 'accidental' return value from the original
SYSV? userspace implementation that just dumped characters that
wouldn't fit in the buffer somewhere.)

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)