From: John W. Linville <linville@tuxdriver.com>
Date: Tue, 8 Nov 2005 20:59:30 +0000 (-0500)
Subject: [PATCH] e1000: zero-out pointers in e1000_free_desc_rings
X-Git-Tag: v2.6.16-rc1~474^2~22^2~7^2~21^2~5^2
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6b27adb607282addcfe2707783dfcc28ba3a753b;p=linux-2.6

[PATCH] e1000: zero-out pointers in e1000_free_desc_rings

In e1000_free_desc_rings, zero-out pointers after the memory they
point to is freed.  The test rings are static and get re-used, and
failures during subsequent test setups can cause e1000_free_desc_rings
to get called with dirty pointers.  Dirty pointers can cause oopses
or crashes...

Signed-off-by: John W. Linville <linville@tuxdriver.com>
---

diff --git a/drivers/net/e1000/e1000_ethtool.c b/drivers/net/e1000/e1000_ethtool.c
index 8584e9382c..8646914964 100644
--- a/drivers/net/e1000/e1000_ethtool.c
+++ b/drivers/net/e1000/e1000_ethtool.c
@@ -960,13 +960,21 @@ e1000_free_desc_rings(struct e1000_adapter *adapter)
 		}
 	}
 
-	if(txdr->desc)
+	if(txdr->desc) {
 		pci_free_consistent(pdev, txdr->size, txdr->desc, txdr->dma);
-	if(rxdr->desc)
+		txdr->desc = NULL;
+	}
+	if(rxdr->desc) {
 		pci_free_consistent(pdev, rxdr->size, rxdr->desc, rxdr->dma);
+		rxdr->desc = NULL;
+	}
 
 	kfree(txdr->buffer_info);
+	txdr->buffer_info = NULL;
+
 	kfree(rxdr->buffer_info);
+	rxdr->buffer_info = NULL;
+
 	return;
 }