linux-kernel - Re: x86_64 system lockup from userspace using setitimer()

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:	Tue, 13 Mar 2007 16:02:03 -0400
From:	Chuck Ebbert <cebbert@...hat.com>
To:	Johannes Bauer <JohannesBauer@....de>
CC:	linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
	schwab@...e.de
Subject: Re: x86_64 system lockup from userspace using setitimer()

Johannes Bauer wrote:
> Dear Community,
> 
> I think I've encountered a bug with the Linux kernel which results in a
> complete system lockup and which can be started without root priviliges.
> It's reproducible with 2.6.20.1 and 2.6.20.2 and only x64_64 seems
> affected.
> 
> Here's the code which triggers the bug (originally found by me using an
> only partly initialized "struct itimerval" structure - hence the strange
> values in it_interval):
> 
> -----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----
> #include <stdio.h>
> #include <sys/time.h>
> #include <unistd.h>
> 
> int main(int argc, char **argv) {
>     struct itimerval tim = {
>         .it_interval = {
>             .tv_sec = 140735669863712,
>             .tv_usec = 4199521
>         },
>         .it_value = {
>             .tv_sec = 0,
>             .tv_usec =  100000
>         }
>     };
>     setitimer(ITIMER_REAL, &tim, NULL);
>     while (1) sleep(1);
>     return 0;
> }
> -----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----8<-----
> 
> Compiled with gcc 4.1.1 with "gcc -O2 -Wall -o crash crash.c".
> 
> The sourcecode can be found at
> http://www.johannes-bauer.com/crash/crash.c and my kernel configuration
> is at http://www.johannes-bauer.com/crash/config
> 
> Any further questions: feel free to ask. Please CC me for any posts in
> this thread.

Could this be fixed by:

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=8bfd9a7a229b5f3d3eda5d7d45c2eebec5b4ba16

[PATCH] hrtimers: prevent possible itimer DoS

?

-
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/