vfio/pci: Init the count variable in collecting hot-reset devices

The count variable is used without initialization, it results in mistakes
in the device counting and crashes the userspace if the get hot reset info
path is triggered.

Fixes: f6944d4a0b87 ("vfio/pci: Collect hot-reset devices to local buffer")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219010
Reported-by: Žilvinas Žaltiena <[email protected]>
Cc: Beld Zhang <[email protected]>
Signed-off-by: Yi Liu <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alex Williamson <[email protected]>

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 987c7921affa6883232ed2f19eb23ca459c43fd1..ba0ce0075b2fb164a5b8ac7d4aa07a53d2b4beb6 100644 (file)
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -1260,7 +1260,7 @@ static int vfio_pci_ioctl_get_pci_hot_reset_info(
        struct vfio_pci_hot_reset_info hdr;
        struct vfio_pci_fill_info fill = {};
        bool slot = false;
-       int ret, count;
+       int ret, count = 0;
 
        if (copy_from_user(&hdr, arg, minsz))
                return -EFAULT;