When ice_adapter_new() fails, the reserved XArray entry created by xa_insert() is not released. This causes subsequent insertions at the same index to return -EBUSY, potentially leading to NULL pointer dereferences. Reorder the operations as suggested by Przemek Kitszel: 1. Check if adapter already exists (xa_load) 2. Reserve the XArray slot (xa_reserve) 3. Allocate the adapter (ice_adapter_new) 4. Store the adapter (xa_store) Fixes: 0f0023c649c7 ("ice: do not init struct ice_adapter more times than needed") Suggested-by: Przemek Kitszel Suggested-by: Jacob Keller Signed-off-by: Haotian Zhang --- Changes in v3: - Reorder xa_load/xa_reserve/ice_adapter_new/xa_store calls as suggested by Przemek Kitszel, instead of just adding xa_release(). Changes in v2: - Instead of checking the return value of xa_store(), fix the real bug where a failed ice_adapter_new() would leave a stale entry in the XArray. - Use xa_release() to clean up the reserved entry, as suggested by Jacob Keller. --- drivers/net/ethernet/intel/ice/ice_adapter.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_adapter.c b/drivers/net/ethernet/intel/ice/ice_adapter.c index b53561c34708..0a8a48cd4bce 100644 --- a/drivers/net/ethernet/intel/ice/ice_adapter.c +++ b/drivers/net/ethernet/intel/ice/ice_adapter.c @@ -99,19 +99,21 @@ struct ice_adapter *ice_adapter_get(struct pci_dev *pdev) index = ice_adapter_xa_index(pdev); scoped_guard(mutex, &ice_adapters_mutex) { - err = xa_insert(&ice_adapters, index, NULL, GFP_KERNEL); - if (err == -EBUSY) { - adapter = xa_load(&ice_adapters, index); + adapter = xa_load(&ice_adapters, index); + if (adapter) { refcount_inc(&adapter->refcount); WARN_ON_ONCE(adapter->index != ice_adapter_index(pdev)); return adapter; } + err = xa_reserve(&ice_adapters, index, GFP_KERNEL); if (err) return ERR_PTR(err); adapter = ice_adapter_new(pdev); - if (!adapter) + if (!adapter) { + xa_release(&ice_adapters, index); return ERR_PTR(-ENOMEM); + } xa_store(&ice_adapters, index, adapter, GFP_KERNEL); } return adapter; -- 2.50.1.windows.1