3.5.7.22 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@xxxxxxxxxx>
commit aab515d7c32a34300312416c50314e755ea6f765 upstream.
AddressSanitizer [1] dynamic checker pointed a potential
out of bound access in leaf_walk_rcu()
We could allocate one more slot in tnode_new() to leave the prefetch()
in-place but it looks not worth the pain.
Bug added in commit 82cfbb008572b ("[IPV4] fib_trie: iterator recode")
[1] :
https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel
Reported-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
net/ipv4/fib_trie.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 30b88d7..424704a 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -71,7 +71,6 @@
#include <linux/init.h>
#include <linux/list.h>
#include <linux/slab.h>
-#include <linux/prefetch.h>
#include <linux/export.h>
#include <net/net_namespace.h>
#include <net/ip.h>
@@ -1772,10 +1771,8 @@ static struct leaf *leaf_walk_rcu(struct tnode *p, struct rt_trie_node *c)
if (!c)
continue;
- if (IS_LEAF(c)) {
- prefetch(rcu_dereference_rtnl(p->child[idx]));
+ if (IS_LEAF(c))
return (struct leaf *) c;
- }
/* Rescan start scanning in new node */
p = (struct tnode *) c;
--
1.8.3.2
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