[PATCH] e100: Add a check after pci_pool_create to avoid null pointer dereference

[PATCH] e100: Add a check after pci_pool_create to avoid null pointer dereference

[Jia-Ju Bai]

The driver lacks the check of nic->cbs_pool after pci_pool_create
in e100_probe. When this function is failed, a null pointer dereference 
occurs when pci_pool_alloc uses nic->cbs_pool in e100_alloc_cbs.
This patch adds a check and related error handling code to fix it.

Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
---
 drivers/net/ethernet/intel/e100.c |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/ethernet/intel/e100.c b/drivers/net/ethernet/intel/e100.c
index d2657a4..767c161 100644
--- a/drivers/net/ethernet/intel/e100.c
+++ b/drivers/net/ethernet/intel/e100.c
@@ -2967,6 +2967,11 @@ static int e100_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 			   nic->params.cbs.max * sizeof(struct cb),
 			   sizeof(u32),
 			   0);
+	if (!nic->cbs_pool) {
+		netif_err(nic, probe, nic->netdev, "Cannot create DMA pool, aborting\n");
+		err = -ENOMEM;
+		goto err_out_pool;
+	}
 	netif_info(nic, probe, nic->netdev,
 		   "addr 0x%llx, irq %d, MAC addr %pM\n",
 		   (unsigned long long)pci_resource_start(pdev, use_io ? 1 : 0),
@@ -2974,6 +2979,8 @@ static int e100_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	return 0;
 
+err_out_pool:
+	unregister_netdev(netdev);
 err_out_free:
 	e100_free(nic);
 err_out_iounmap:
-- 
1.7.9.5

RE: [Intel-wired-lan] [PATCH] e100: Add a check after pci_pool_create to avoid null pointer dereference

[Brown, Aaron F]

> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@lists.osuosl.org] On
> Behalf Of Jia-Ju Bai
> Sent: Sunday, August 02, 2015 7:17 PM
> To: Kirsher, Jeffrey T; Brandeburg, Jesse
> Cc: netdev@vger.kernel.org; Jia-Ju Bai; intel-wired-lan@lists.osuosl.org;
> linux-kernel@vger.kernel.org
> Subject: [Intel-wired-lan] [PATCH] e100: Add a check after pci_pool_create
> to avoid null pointer dereference
> 
> The driver lacks the check of nic->cbs_pool after pci_pool_create
> in e100_probe. When this function is failed, a null pointer dereference
> occurs when pci_pool_alloc uses nic->cbs_pool in e100_alloc_cbs.
> This patch adds a check and related error handling code to fix it.
> 
> Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
> ---
>  drivers/net/ethernet/intel/e100.c |    7 +++++++
>  1 file changed, 7 insertions(+)

Tested-by: Aaron Brown <aaron.f.brown@intel.com>