[PATCH] umem: don't return zero on failure paths in mm_pci_probe()

From: Alexey Khoroshilov
Date: Wed Jul 01 2015 - 17:23:35 EST


If pci_alloc_consistent() or blk_alloc_queue() failed,
mm_pci_probe() breaks off initialization, deallocates
resources, but returns zero.

The patch adds -ENOMEM as a return value in these cases.
By the way, it adds blk_cleanup_queue() and pci_disable_device()
to fix leaks in failure handling code.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>
---
drivers/block/umem.c | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/block/umem.c b/drivers/block/umem.c
index 4cf81b5bf0f7..960a3cadcd6b 100644
--- a/drivers/block/umem.c
+++ b/drivers/block/umem.c
@@ -808,12 +808,14 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
pci_write_config_byte(dev, PCI_LATENCY_TIMER, 0xF8);
pci_set_master(dev);

- card->dev = dev;
+ card->dev = dev;

csr_base = pci_resource_start(dev, 0);
csr_len = pci_resource_len(dev, 0);
- if (!csr_base || !csr_len)
- return -ENODEV;
+ if (!csr_base || !csr_len) {
+ ret = -ENODEV;
+ goto failed_pci;
+ }

dev_printk(KERN_INFO, &dev->dev,
"Micro Memory(tm) controller found (PCI Mem Module (Battery Backup))\n");
@@ -821,7 +823,8 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
if (pci_set_dma_mask(dev, DMA_BIT_MASK(64)) &&
pci_set_dma_mask(dev, DMA_BIT_MASK(32))) {
dev_printk(KERN_WARNING, &dev->dev, "NO suitable DMA found\n");
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto failed_pci;
}

ret = pci_request_regions(dev, DRIVER_NAME);
@@ -836,7 +839,6 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
dev_printk(KERN_ERR, &card->dev->dev,
"Unable to remap memory region\n");
ret = -ENOMEM;
-
goto failed_remap_csr;
}

@@ -881,6 +883,7 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
if (card->mm_pages[0].desc == NULL ||
card->mm_pages[1].desc == NULL) {
dev_printk(KERN_ERR, &card->dev->dev, "alloc failed\n");
+ ret = -ENOMEM;
goto failed_alloc;
}
reset_page(&card->mm_pages[0]);
@@ -891,8 +894,10 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
card->biotail = &card->bio;

card->queue = blk_alloc_queue(GFP_KERNEL);
- if (!card->queue)
+ if (!card->queue) {
+ ret = -ENOMEM;
goto failed_alloc;
+ }

blk_queue_make_request(card->queue, mm_make_request);
card->queue->queue_lock = &card->lock;
@@ -1002,6 +1007,7 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
return 0;

failed_req_irq:
+ blk_cleanup_queue(card->queue);
failed_alloc:
if (card->mm_pages[0].desc)
pci_free_consistent(card->dev, PAGE_SIZE*2,
@@ -1016,6 +1022,8 @@ static int mm_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
failed_remap_csr:
pci_release_regions(dev);
failed_req_csr:
+ failed_pci:
+ pci_disable_device(dev);

return ret;
}
--
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/