NVMe: Prevent possible NULL pointer dereference

kmalloc() used by the nvme_alloc_iod() to allocate memory for 'iod'
can fail. So check the return value.

Signed-off-by: Santosh Y <santosh.sy@samsung.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index b82155888845..872d8e42d008 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -1488,7 +1488,11 @@ struct nvme_iod *nvme_map_user_pages(struct nvme_dev *dev, int write,
                 goto put_pages;
         }
 
+        err = -ENOMEM;
         iod = nvme_alloc_iod(count, length, GFP_KERNEL);
+        if (!iod)
+                goto put_pages;
+
         sg = iod->sg;
         sg_init_table(sg, count);
         for (i = 0; i < count; i++) {
@@ -1501,7 +1505,6 @@ struct nvme_iod *nvme_map_user_pages(struct nvme_dev *dev, int write,
         sg_mark_end(&sg[i - 1]);
         iod->nents = count;
 
-        err = -ENOMEM;
         nents = dma_map_sg(&dev->pci_dev->dev, sg, count,
                                 write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
         if (!nents)