netdev - [PATCH] tc35815: Remove a wrong netif_wake_queue() call which triggers BUG

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-next>] [day] [month] [year] [list]

Date:	Sat, 20 Feb 2010 00:13:58 +0900
From:	Atsushi Nemoto <anemo@....ocn.ne.jp>
To:	netdev@...r.kernel.org
Cc:	David Miller <davem@...emloft.net>,
	Ralf Roesch <ralf.roesch@...gmbh.de>
Subject: [PATCH] tc35815: Remove a wrong netif_wake_queue() call which triggers BUG_ON

The netif_wake_queue() is called correctly (i.e. only on !txfull
condition) from txdone routine.  So Unconditional call to the
netif_wake_queue() here is wrong.  This might cause calling of
start_xmit routine on txfull state and trigger BUG_ON.

This bug does not happen when NAPI disabled.  After txdone there
must be at least one free tx slot.  But with NAPI, this is not
true anymore and the BUG_ON can hits on heavy load.

In this driver NAPI was enabled on 2.6.33-rc1 so this is
regression from 2.6.32 kernel.

Reported-by: Ralf Roesch <ralf.roesch@...gmbh.de>
Signed-off-by: Atsushi Nemoto <anemo@....ocn.ne.jp>
---
 drivers/net/tc35815.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/drivers/net/tc35815.c b/drivers/net/tc35815.c
index 75a669d..d71c197 100644
--- a/drivers/net/tc35815.c
+++ b/drivers/net/tc35815.c
@@ -1437,7 +1437,6 @@ static int tc35815_do_interrupt(struct net_device *dev, u32 status, int limit)
 		/* Transmit complete. */
 		lp->lstats.tx_ints++;
 		tc35815_txdone(dev);
-		netif_wake_queue(dev);
 		if (ret < 0)
 			ret = 0;
 	}
-- 
1.5.6.5

--
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