The "array_count" value comes from the copy_from_user() in
vfio_pci_ioctl_pci_hot_reset().  If the user passes a value larger than
INT_MAX then we'll pass a negative value to kcalloc() which triggers an
allocation failure and a stack trace.

It's better to make the type unsigned so that if (array_count > count)
returns -EINVAL instead.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/vfio/pci/vfio_pci_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 077d4a2629c8..1ab58da9f38a 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -1324,7 +1324,7 @@ static int vfio_pci_ioctl_get_pci_hot_reset_info(
 
 static int
 vfio_pci_ioctl_pci_hot_reset_groups(struct vfio_pci_core_device *vdev,
-				    int array_count, bool slot,
+				    u32 array_count, bool slot,
 				    struct vfio_pci_hot_reset __user *arg)
 {
 	int32_t *group_fds;
-- 
2.45.2

On Thu, 12 Sep 2024 11:49:10 +0300
Dan Carpenter <dan.carpenter@linaro.org> wrote:

> The "array_count" value comes from the copy_from_user() in
> vfio_pci_ioctl_pci_hot_reset().  If the user passes a value larger than
> INT_MAX then we'll pass a negative value to kcalloc() which triggers an
> allocation failure and a stack trace.
> 
> It's better to make the type unsigned so that if (array_count > count)
> returns -EINVAL instead.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
>  drivers/vfio/pci/vfio_pci_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
> index 077d4a2629c8..1ab58da9f38a 100644
> --- a/drivers/vfio/pci/vfio_pci_core.c
> +++ b/drivers/vfio/pci/vfio_pci_core.c
> @@ -1324,7 +1324,7 @@ static int vfio_pci_ioctl_get_pci_hot_reset_info(
>  
>  static int
>  vfio_pci_ioctl_pci_hot_reset_groups(struct vfio_pci_core_device *vdev,
> -				    int array_count, bool slot,
> +				    u32 array_count, bool slot,
>  				    struct vfio_pci_hot_reset __user *arg)
>  {
>  	int32_t *group_fds;

Applied to vfio next branch for v6.12.  Thanks!

Alex

On Thu, Sep 12, 2024 at 11:49:10AM +0300, Dan Carpenter wrote:
> The "array_count" value comes from the copy_from_user() in
> vfio_pci_ioctl_pci_hot_reset().  If the user passes a value larger than
> INT_MAX then we'll pass a negative value to kcalloc() which triggers an
> allocation failure and a stack trace.
> 
> It's better to make the type unsigned so that if (array_count > count)
> returns -EINVAL instead.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
>  drivers/vfio/pci/vfio_pci_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason