[Intel-wired-lan] [bug report] idpf: add core init and interrupt request

[Dan Carpenter]

Hello Pavan Kumar Linga,

Commit 4930fbf419a7 ("idpf: add core init and interrupt request")
from Aug 7, 2023 (linux-next), leads to the following Smatch static
checker warning:

	drivers/net/ethernet/intel/idpf/idpf_lib.c:417 idpf_intr_req()
	error: we previously assumed 'adapter->req_vec_chunks' could be null (see line 360)

drivers/net/ethernet/intel/idpf/idpf_lib.c
    315 int idpf_intr_req(struct idpf_adapter *adapter)
    316 {
    317         u16 default_vports = idpf_get_default_vports(adapter);
    318         int num_q_vecs, total_vecs, num_vec_ids;
    319         int min_vectors, v_actual, err;
    320         unsigned int vector;
    321         u16 *vecids;
    322 
    323         total_vecs = idpf_get_reserved_vecs(adapter);
    324         num_q_vecs = total_vecs - IDPF_MBX_Q_VEC;
    325 
    326         err = idpf_send_alloc_vectors_msg(adapter, num_q_vecs);
    327         if (err) {
    328                 dev_err(&adapter->pdev->dev,
    329                         "Failed to allocate %d vectors: %d\n", num_q_vecs, err);
    330 
    331                 return -EAGAIN;
    332         }
    333 
    334         min_vectors = IDPF_MBX_Q_VEC + IDPF_MIN_Q_VEC * default_vports;
    335         v_actual = pci_alloc_irq_vectors(adapter->pdev, min_vectors,
    336                                          total_vecs, PCI_IRQ_MSIX);
    337         if (v_actual < min_vectors) {
    338                 dev_err(&adapter->pdev->dev, "Failed to allocate MSIX vectors: %d\n",
    339                         v_actual);
    340                 err = -EAGAIN;
    341                 goto send_dealloc_vecs;
    342         }
    343 
    344         adapter->msix_entries = kcalloc(v_actual, sizeof(struct msix_entry),
    345                                         GFP_KERNEL);
    346 
    347         if (!adapter->msix_entries) {
    348                 err = -ENOMEM;
    349                 goto free_irq;
    350         }
    351 
    352         idpf_set_mb_vec_id(adapter);
    353 
    354         vecids = kcalloc(total_vecs, sizeof(u16), GFP_KERNEL);
    355         if (!vecids) {
    356                 err = -ENOMEM;
    357                 goto free_msix;
    358         }
    359 
    360         if (adapter->req_vec_chunks) {
                    ^^^^^^^^^^^^^^^^^^^^^^^
If ->req_vec_chunks is NULL the error handling will crash

    361                 struct virtchnl2_vector_chunks *vchunks;
    362                 struct virtchnl2_alloc_vectors *ac;
    363 
    364                 ac = adapter->req_vec_chunks;
    365                 vchunks = &ac->vchunks;
    366 
    367                 num_vec_ids = idpf_get_vec_ids(adapter, vecids, total_vecs,
    368                                                vchunks);
    369                 if (num_vec_ids < v_actual) {
    370                         err = -EINVAL;
    371                         goto free_vecids;
    372                 }
    373         } else {
    374                 int i;
    375 
    376                 for (i = 0; i < v_actual; i++)
    377                         vecids[i] = i;
    378         }
    379 
    380         for (vector = 0; vector < v_actual; vector++) {
    381                 adapter->msix_entries[vector].entry = vecids[vector];
    382                 adapter->msix_entries[vector].vector =
    383                         pci_irq_vector(adapter->pdev, vector);
    384         }
    385 
    386         adapter->num_req_msix = total_vecs;
    387         adapter->num_msix_entries = v_actual;
    388         /* 'num_avail_msix' is used to distribute excess vectors to the vports
    389          * after considering the minimum vectors required per each default
    390          * vport
    391          */
    392         adapter->num_avail_msix = v_actual - min_vectors;
    393 
    394         /* Fill MSIX vector lifo stack with vector indexes */
    395         err = idpf_init_vector_stack(adapter);
    396         if (err)
    397                 goto free_vecids;
    398 
    399         err = idpf_mb_intr_init(adapter);
    400         if (err)
    401                 goto deinit_vec_stack;
    402         idpf_mb_irq_enable(adapter);
    403         kfree(vecids);
    404 
    405         return 0;
    406 
    407 deinit_vec_stack:
    408         idpf_deinit_vector_stack(adapter);
    409 free_vecids:
    410         kfree(vecids);
    411 free_msix:
    412         kfree(adapter->msix_entries);
    413         adapter->msix_entries = NULL;
    414 free_irq:
    415         pci_free_irq_vectors(adapter->pdev);
    416 send_dealloc_vecs:
--> 417         idpf_send_dealloc_vectors_msg(adapter);
                                              ^^^^^^^
Inside this function

    418 
    419         return err;
    420 }

regards,
dan carpenter