netdev - [ 57/80] batman-adv: fix random jitter calculation

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>] [day] [month] [year] [list]

Date:	Wed,  9 Jan 2013 12:35:49 -0800
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	alan@...rguk.ukuu.org.uk, Akinobu Mita <akinobu.mita@...il.com>,
	Antonio Quartulli <ordex@...istici.org>,
	Marek Lindner <lindner_marek@...oo.de>,
	Simon Wunderlich <siwu@....tu-chemnitz.de>,
	"David S. Miller" <davem@...emloft.net>,
	b.a.t.m.a.n@...ts.open-mesh.org, netdev@...r.kernel.org
Subject: [ 57/80] batman-adv: fix random jitter calculation

3.4-stable review patch.  If anyone has any objections, please let me know.

------------------


From: Akinobu Mita <akinobu.mita@...il.com>

[ Upstream commit 143cdd8f33909ff5a153e3f02048738c5964ba26 ]

batadv_iv_ogm_emit_send_time() attempts to calculates a random integer
in the range of 'orig_interval +- BATADV_JITTER' by the below lines.

        msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
        msecs += (random32() % 2 * BATADV_JITTER);

But it actually gets 'orig_interval' or 'orig_interval - BATADV_JITTER'
because '%' and '*' have same precedence and associativity is
left-to-right.

This adds the parentheses at the appropriate position so that it matches
original intension.

Signed-off-by: Akinobu Mita <akinobu.mita@...il.com>
Acked-by: Antonio Quartulli <ordex@...istici.org>
Cc: Marek Lindner <lindner_marek@...oo.de>
Cc: Simon Wunderlich <siwu@....tu-chemnitz.de>
Cc: Antonio Quartulli <ordex@...istici.org>
Cc: b.a.t.m.a.n@...ts.open-mesh.org
Cc: "David S. Miller" <davem@...emloft.net>
Cc: netdev@...r.kernel.org
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 net/batman-adv/bat_iv_ogm.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -72,7 +72,7 @@ static unsigned long bat_iv_ogm_emit_sen
 {
 	return jiffies + msecs_to_jiffies(
 		   atomic_read(&bat_priv->orig_interval) -
-		   JITTER + (random32() % 2*JITTER));
+		   JITTER + (random32() % (2*JITTER)));
 }
 
 /* when do we schedule a ogm packet to be sent */


--
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