[PATCH] spi: mchp-pci1xxx: Fix a possible null pointer dereference in pci1xxx_spi_probe

[PATCH] spi: mchp-pci1xxx: Fix a possible null pointer dereference in pci1xxx_spi_probe

[Huai-Yuan Liu]

In function pci1xxxx_spi_probe, there is a potential null pointer that 
may be caused by a failed memory allocation by the function devm_kzalloc. 
Hence, a null pointer check needs to be added to prevent null pointer
dereferencing later in the code.

To fix this issue, spi_bus->spi_int[iter] should be checked. The memory
allocated by devm_kzalloc will be automatically released, so just directly
return -ENOMEM without worrying about memory leaks.

Fixes: 1cc0cbea7167 ("spi: microchip: pci1xxxx: Add driver for SPI controller of PCI1XXXX PCIe switch")
Signed-off-by: Huai-Yuan Liu <qq810974084@gmail.com>
---
 drivers/spi/spi-pci1xxxx.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/spi/spi-pci1xxxx.c b/drivers/spi/spi-pci1xxxx.c
index 5b2d3e4e21b7..5a4226682052 100644
--- a/drivers/spi/spi-pci1xxxx.c
+++ b/drivers/spi/spi-pci1xxxx.c
@@ -275,6 +275,8 @@ static int pci1xxxx_spi_probe(struct pci_dev *pdev, const struct pci_device_id *
 		spi_bus->spi_int[iter] = devm_kzalloc(&pdev->dev,
 						      sizeof(struct pci1xxxx_spi_internal),
 						      GFP_KERNEL);
+		if (!spi_bus->spi_int[iter])
+			return -ENOMEM;
 		spi_sub_ptr = spi_bus->spi_int[iter];
 		spi_sub_ptr->spi_host = devm_spi_alloc_host(dev, sizeof(struct spi_controller));
 		if (!spi_sub_ptr->spi_host)
-- 
2.34.1

Re: [PATCH] spi: mchp-pci1xxx: Fix a possible null pointer dereference in pci1xxx_spi_probe

[Mark Brown]

On Wed, 03 Apr 2024 09:42:21 +0800, Huai-Yuan Liu wrote:
> In function pci1xxxx_spi_probe, there is a potential null pointer that
> may be caused by a failed memory allocation by the function devm_kzalloc.
> Hence, a null pointer check needs to be added to prevent null pointer
> dereferencing later in the code.
> 
> To fix this issue, spi_bus->spi_int[iter] should be checked. The memory
> allocated by devm_kzalloc will be automatically released, so just directly
> return -ENOMEM without worrying about memory leaks.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: mchp-pci1xxx: Fix a possible null pointer dereference in pci1xxx_spi_probe
      commit: 1f886a7bfb3faf4c1021e73f045538008ce7634e

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark