netdev - Re: net-next kernel NULL pointer dereference at fib_rules

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, 10 Jul 2012 09:44:28 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	ogerlitz@...lanox.com
Cc:	netdev@...r.kernel.org, shlomop@...lanox.com, amirv@...lanox.com,
	erezsh@...lanox.com
Subject: Re: net-next kernel NULL pointer dereference at fib_rules_tclass 

From: Or Gerlitz <ogerlitz@...lanox.com>
Date: Tue, 10 Jul 2012 10:16:55 +0300

> Starting system logger: BUG: unable to handle kernel NULL pointer dereference at 00000000000000ac
> IP: [<ffffffff81320393>] fib_rules_tclass+0xf/0x17

Ok, fib_rules_tclass() checks for res->r being NULL and only
dereferences it if it is not.

fib4_rule->tclassid has offset ~0x8c on x86-64, and this fault
address is 0x10 bytes off.

Does this patch fix the problem?

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 539c672..000c467 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -230,6 +230,7 @@ static inline int fib_lookup(struct net *net, struct flowi4 *flp,
 			     struct fib_result *res)
 {
 	if (!net->ipv4.fib_has_custom_rules) {
+		res->r = NULL;
 		if (net->ipv4.fib_local &&
 		    !fib_table_lookup(net->ipv4.fib_local, flp, res,
 				      FIB_LOOKUP_NOREF))
--
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