From: Matthew Wilcox (Oracle) willy@infradead.org
[ Upstream commit b7e9728f3d7fc5c5c8508d99f1675212af5cfd49 ]
Attempting to allocate an entry at 0xffffffff when one is already present would succeed in allocating one at 2^32, which would confuse everything. Return -ENOSPC in this case, as expected.
Signed-off-by: Matthew Wilcox (Oracle) willy@infradead.org Signed-off-by: Sasha Levin sashal@kernel.org --- lib/radix-tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 18c1dfbb17654..c8fa1d2745302 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -1529,7 +1529,7 @@ void __rcu **idr_get_free(struct radix_tree_root *root, offset = radix_tree_find_next_bit(node, IDR_FREE, offset + 1); start = next_index(start, node, offset); - if (start > max) + if (start > max || start == 0) return ERR_PTR(-ENOSPC); while (offset == RADIX_TREE_MAP_SIZE) { offset = node->offset + 1;