netdev - Re: [REGRESSION][PATCH] bpf_jit drops the ball on indirect negative mem references

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: <1332965129.2325.12.camel@edumazet-glaptop>
Date:	Wed, 28 Mar 2012 22:05:29 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Jan Seiffert <kaffeemonster@...glemail.com>
Cc:	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	"David S. Miller" <davem@...emloft.net>,
	Matt Evans <matt@...abs.org>
Subject: Re: [REGRESSION][PATCH] bpf_jit drops the ball on indirect
 negative mem references

On Wed, 2012-03-28 at 21:15 +0200, Jan Seiffert wrote:
> Consider the following test program:
> 
> #include <stdio.h>
> #include <sys/types.h>
> #include <sys/socket.h>
> #include <netinet/in.h>
> #include <pcap-bpf.h>
> 
> #define die(x) do {perror(x); return 1;} while (0)
> struct bpf_insn udp_filter[] = {
> 	/*   0 */ BPF_STMT(BPF_LDX|BPF_W|BPF_IMM, -1048576+(0)), /* leax	net[0] */
> 	/*   1 */ BPF_STMT(BPF_LD|BPF_B|BPF_IND, 0),             /* ldb	[x+0] */
> 	/*   2 */ BPF_STMT(BPF_RET|BPF_A, 0),                    /* ret	a */
> };

When this point was raised some weeks ago, we wanted to see a _real_ use
of negative mem reference.

You provide a test program but what this filter is supposed to do
exactly ?



--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html