linux-kernel - Re: [PATCH] sysctl: add bound to panic

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]

Date:   Fri, 10 Jul 2020 12:28:03 +0100
From:   Matthew Wilcox <willy@...radead.org>
To:     Randy Dunlap <rdunlap@...radead.org>
Cc:     Changming Liu <charley.ashbringer@...il.com>,
        keescook@...omium.org, mcgrof@...nel.org, yzaikin@...gle.com,
        linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org
Subject: Re: [PATCH] sysctl: add bound to panic_timeout to prevent overflow

On Thu, Jul 09, 2020 at 08:31:39PM -0700, Randy Dunlap wrote:
> > +/* this is needed for setting boundery for panic_timeout to prevent it from overflow*/
> 
>                                  boundary (or max value)                       overflow */
> 
> > +static int panic_time_max = INT_MAX / 1000;

Or just simplify the comment.

/* Prevent overflow in panic() */

Or perhaps better, fix panic() to not overflow.

-		for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) {
+		for (i = 0; i / 1000 < panic_timeout; i += PANIC_TIMER_STEP) {

you probably also want to change i to be a long long or the loop may never
terminate.