Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit aab515d7 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

fib_trie: remove potential out of bound access 

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 82cfbb00 ("[IPV4] fib_trie: iterator recode")

[1] :
https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel



Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3b380877

net/ipv4/fib_trie.c

+1 −4
Original line number Diff line number Diff line
@@ -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>
@@ -1761,10 +1760,8 @@ 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;