Patchwork [2/3,-next] 6LoWPAN: use the _safe version of list_for_each

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Submitter Dan Carpenter
Date Aug. 30, 2011, 1:46 p.m.
Message ID <20110830134640.GI3705@shale.localdomain>
Download mbox | patch
Permalink /patch/112309/
State Accepted
Delegated to: David Miller
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Comments

Dan Carpenter - Aug. 30, 2011, 1:46 p.m.
When we kfree(entry) that causes a use-after-free bug so we have to
use list_for_each_entry_safe() safe here.

Signed-off-by: Dan Carpenter <error27@gmail.com>
---
Curly parens are not needed here, but kernel style is to use them for
multi-line indent blocks.

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David Miller - Sept. 15, 2011, 7:42 p.m.
From: Dan Carpenter <error27@gmail.com>
Date: Tue, 30 Aug 2011 16:46:40 +0300

> When we kfree(entry) that causes a use-after-free bug so we have to
> use list_for_each_entry_safe() safe here.
> 
> Signed-off-by: Dan Carpenter <error27@gmail.com>

Applied.
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Patch

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index cf304cc..5dc0489 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -813,15 +813,17 @@  static void lowpan_dellink(struct net_device *dev, struct list_head *head)
 	struct lowpan_dev_info *lowpan_dev = lowpan_dev_info(dev);
 	struct net_device *real_dev = lowpan_dev->real_dev;
 	struct lowpan_dev_record *entry;
+	struct lowpan_dev_record *tmp;
 
 	ASSERT_RTNL();
 
 	mutex_lock(&lowpan_dev_info(dev)->dev_list_mtx);
-	list_for_each_entry(entry, &lowpan_devices, list)
+	list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
 		if (entry->ldev == dev) {
 			list_del(&entry->list);
 			kfree(entry);
 		}
+	}
 	mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
 
 	mutex_destroy(&lowpan_dev_info(dev)->dev_list_mtx);