[FIB]: full_children & empty_children should be uint, not ushort
If declared as unsigned short, these fields can overflow, and whole
trie logic is broken. I could not make the machine crash, but some
tnode can never be freed.
Note for 64 bit arches : By reordering t_key and parent in [node,
leaf, tnode] structures, we can use 32 bits hole after t_key so that
sizeof(struct tnode) doesnt change after this patch.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index da6681d..18fb739 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -97,13 +97,13 @@
#define IS_LEAF(n) (n->parent & T_LEAF)
struct node {
- t_key key;
unsigned long parent;
+ t_key key;
};
struct leaf {
- t_key key;
unsigned long parent;
+ t_key key;
struct hlist_head list;
struct rcu_head rcu;
};
@@ -116,12 +116,12 @@
};
struct tnode {
- t_key key;
unsigned long parent;
+ t_key key;
unsigned char pos; /* 2log(KEYLENGTH) bits needed */
unsigned char bits; /* 2log(KEYLENGTH) bits needed */
- unsigned short full_children; /* KEYLENGTH bits needed */
- unsigned short empty_children; /* KEYLENGTH bits needed */
+ unsigned int full_children; /* KEYLENGTH bits needed */
+ unsigned int empty_children; /* KEYLENGTH bits needed */
struct rcu_head rcu;
struct node *child[0];
};
@@ -329,12 +329,12 @@
call_rcu(&leaf->rcu, __leaf_info_free_rcu);
}
-static struct tnode *tnode_alloc(unsigned int size)
+static struct tnode *tnode_alloc(size_t size)
{
struct page *pages;
if (size <= PAGE_SIZE)
- return kcalloc(size, 1, GFP_KERNEL);
+ return kzalloc(size, GFP_KERNEL);
pages = alloc_pages(GFP_KERNEL|__GFP_ZERO, get_order(size));
if (!pages)
@@ -346,8 +346,8 @@
static void __tnode_free_rcu(struct rcu_head *head)
{
struct tnode *tn = container_of(head, struct tnode, rcu);
- unsigned int size = sizeof(struct tnode) +
- (1 << tn->bits) * sizeof(struct node *);
+ size_t size = sizeof(struct tnode) +
+ (sizeof(struct node *) << tn->bits);
if (size <= PAGE_SIZE)
kfree(tn);
@@ -386,8 +386,7 @@
static struct tnode* tnode_new(t_key key, int pos, int bits)
{
- int nchildren = 1<<bits;
- int sz = sizeof(struct tnode) + nchildren * sizeof(struct node *);
+ size_t sz = sizeof(struct tnode) + (sizeof(struct node *) << bits);
struct tnode *tn = tnode_alloc(sz);
if (tn) {
@@ -399,8 +398,8 @@
tn->empty_children = 1<<bits;
}
- pr_debug("AT %p s=%u %u\n", tn, (unsigned int) sizeof(struct tnode),
- (unsigned int) (sizeof(struct node) * 1<<bits));
+ pr_debug("AT %p s=%u %lu\n", tn, (unsigned int) sizeof(struct tnode),
+ (unsigned long) (sizeof(struct node) << bits));
return tn;
}