1. Race in mempool_resize: memcpy can copy at the end of the kmalloced elements.
2. when new_min_nr is same as min_nr, instead of reallocate and copy, just return,
changed '<' to '<='.
3. Changed while condition to the same sense of if condition from '>' to '<'; it is
easy to think with only one of the left and right brains at a time.
Signed-off-by: Prasanna Meda <[email protected]>
--- Linux/mm/mempool.c Mon Feb 14 23:03:00 2005
+++ linux/mm/mempool.c Mon Feb 14 23:03:04 2005
@@ -114,8 +114,8 @@
BUG_ON(new_min_nr <= 0);
spin_lock_irqsave(&pool->lock, flags);
- if (new_min_nr < pool->min_nr) {
- while (pool->curr_nr > new_min_nr) {
+ if (new_min_nr <= pool->min_nr) {
+ while (new_min_nr < pool->curr_nr) {
element = remove_element(pool);
spin_unlock_irqrestore(&pool->lock, flags);
pool->free(element, pool->pool_data);
@@ -132,6 +132,12 @@
return -ENOMEM;
spin_lock_irqsave(&pool->lock, flags);
+ if (unlikely(new_min_nr <= pool->min_nr)) {
+ /* Raced, other resize will do our work */
+ spin_unlock_irqrestore(&pool->lock, flags);
+ kfree(new_elements);
+ goto out;
+ }
memcpy(new_elements, pool->elements,
pool->curr_nr * sizeof(*new_elements));
kfree(pool->elements);
@@ -149,7 +155,7 @@
} else {
spin_unlock_irqrestore(&pool->lock, flags);
pool->free(element, pool->pool_data); /* Raced */
- spin_lock_irqsave(&pool->lock, flags);
+ goto out;
}
}
out_unlock: