linux-kernel - [PATCH 5/6] mISDN: Do not disable IRQ in ph_data

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, 9 Jun 2009 14:38:39 +0200
From:	Karsten Keil <keil@...systems.de>
To:	linux-kernel@...r.kernel.org
Cc:	netdev@...r.kernel.org, David Miller <davem@...emloft.net>,
	i4ldeveloper@...tserv.isdn4linux.de
Subject: [PATCH 5/6] mISDN: Do not disable IRQ in ph_data_ind()

This fix triggering the WARN_ON_ONCE(in_irq() || irqs_disabled()); in
local_bh_enable().

Here is no need to grab this lock, this was wrong at all and may
cause a deadlock and access to freed memory, since on a TEI remove
the current listelement can be deleted under us. So this is clearly
a case for list_for_each_entry_safe.

Signed-off-by: Karsten Keil <keil@...systems.de>
---
 drivers/isdn/mISDN/tei.c |    7 ++-----
 1 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/isdn/mISDN/tei.c b/drivers/isdn/mISDN/tei.c
index bfcdd97..e04bad6 100644
--- a/drivers/isdn/mISDN/tei.c
+++ b/drivers/isdn/mISDN/tei.c
@@ -862,8 +862,7 @@ static int
 ph_data_ind(struct manager *mgr, struct sk_buff *skb)
 {
 	int		ret = -EINVAL;
-	struct layer2	*l2;
-	u_long		flags;
+	struct layer2	*l2, *nl2;
 	u_char		mt;
 
 	if (skb->len < 8) {
@@ -908,11 +907,9 @@ ph_data_ind(struct manager *mgr, struct sk_buff *skb)
 		new_tei_req(mgr, &skb->data[4]);
 		goto done;
 	}
-	read_lock_irqsave(&mgr->lock, flags);
-	list_for_each_entry(l2, &mgr->layer2, list) {
+	list_for_each_entry_safe(l2, nl2, &mgr->layer2, list) {
 		tei_ph_data_ind(l2->tm, mt, &skb->data[4], skb->len - 4);
 	}
-	read_unlock_irqrestore(&mgr->lock, flags);
 done:
 	return ret;
 }
-- 
1.6.0.2

--
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/