linux-kernel - Re: [PATCH 7/11] 2.6.18-mm3 pktcdvd: make procfs interface optional

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: <m3bqoqmt3e.fsf@telia.com>
Date:	05 Oct 2006 21:59:49 +0200
From:	Peter Osterlund <petero2@...ia.com>
To:	balagi@...tmail.de
Cc:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"akpm@...l.org" <akpm@...l.org>
Subject: Re: [PATCH 7/11] 2.6.18-mm3 pktcdvd: make procfs interface optional

"Thomas Maier" <balagi@...tmail.de> writes:

> this patch makes the procfs interface optional and groups
> the procfs functions together.
> New kernel config parameter: CDROM_PKTCDVD_PROCINTF

Given the fact that Linus doesn't allow breaking user space tools
unless absolutely necessary, I don't think it makes sense to be able
to disable the character device control code.

The /proc/driver/pktcdvd/pktcdvd? file only contains debugging stuff
though, and the main reason it's not already in debugfs is that
debugfs didn't exist when Jens wrote this driver.

Therefore a patch that unconditionally moves
/proc/driver/pktcdvd/pktcdvd? to debugfs would make a lot of sense.

Also, the current change has another problem:

static int pkt_seq_show(struct seq_file *m, void *p)
+{
+       struct pktcdvd_device *pd = m->private;
+       char buf[1024];
+
+       pkt_print_info(pd, buf, sizeof(buf));
+       seq_printf(m, "%s", buf);
+       return 0;
+}

This wastes 1K stack space, and it can corrupt the stack if the
pkt_print_info() function wants to write more than 1K data.

Unconditionally moving to debugfs would remove the need for the
pkt_print_info() function so the buf array wouldn't be needed any
more.

-- 
Peter Osterlund - petero2@...ia.com
http://web.telia.com/~u89404340
-
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/