[patch 23/28] ehea: fix invalid pointer access

Greg KH
2009-05-14T23:09:07Z

[-- Attachment #1: ehea-fix-invalid-pointer-access.patch --]
[-- Type: text/plain, Size: 1877 bytes --]

2.6.27-stable review patch. If anyone has any objections, please let us know.

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

From: Hannes Hering <hering2@de.ibm.com>

commit 0b2febf38a33d7c40fb7bb4a58c113a1fa33c412 upstream.

This patch fixes an invalid pointer access in case the receive queue
holds no pointer to the next skb when the queue is empty.

Signed-off-by: Hannes Hering <hering2@de.ibm.com>
Signed-off-by: Jan-Bernd Themann <themann@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/net/ehea/ehea_main.c | 31 ++++++++++++++++++-------------
1 file changed, 18 insertions(+), 13 deletions(-)

--- a/drivers/net/ehea/ehea_main.c
+++ b/drivers/net/ehea/ehea_main.c
@@ -529,14 +529,17 @@ static inline struct sk_buff *get_skb_by
x &= (arr_len - 1);

pref = skb_array[x];
- prefetchw(pref);
- prefetchw(pref + EHEA_CACHE_LINE);
+ if (pref) {
+ prefetchw(pref);
+ prefetchw(pref + EHEA_CACHE_LINE);
+
+ pref = (skb_array[x]->data);
+ prefetch(pref);
+ prefetch(pref + EHEA_CACHE_LINE);
+ prefetch(pref + EHEA_CACHE_LINE * 2);
+ prefetch(pref + EHEA_CACHE_LINE * 3);
+ }

- pref = (skb_array[x]->data);
- prefetch(pref);
- prefetch(pref + EHEA_CACHE_LINE);
- prefetch(pref + EHEA_CACHE_LINE * 2);
- prefetch(pref + EHEA_CACHE_LINE * 3);
skb = skb_array[skb_index];
skb_array[skb_index] = NULL;
return skb;
@@ -553,12 +556,14 @@ static inline struct sk_buff *get_skb_by
x &= (arr_len - 1);

pref = skb_array[x];
- prefetchw(pref);
- prefetchw(pref + EHEA_CACHE_LINE);
-
- pref = (skb_array[x]->data);
- prefetchw(pref);
- prefetchw(pref + EHEA_CACHE_LINE);
+ if (pref) {
+ prefetchw(pref);
+ prefetchw(pref + EHEA_CACHE_LINE);
+
+ pref = (skb_array[x]->data);
+ prefetchw(pref);
+ prefetchw(pref + EHEA_CACHE_LINE);
+ }

skb = skb_array[wqe_index];
skb_array[wqe_index] = NULL;