From: Zhenyu Wang <zhenyuw@linux.intel.com>
Date: Thu, 25 Nov 2021 13:13:28 +0800
Subject: vfio/pci: Fix OpRegion read
Git-commit: 8704e89349080bd640d1755c46d8cdc359a89748
Patch-mainline: v5.16-rc4
References: bsc#1205701
This is to fix incorrect pointer arithmetic which caused wrong
OpRegion version returned, then VM driver got error to get wanted
VBT block. We need to be safe to return correct data, so force
pointer type for byte access.
Fixes: 49ba1a2976c8 ("vfio/pci: Add OpRegion 2.0+ Extended VBT support.")
Cc: Colin Xu <colin.xu@gmail.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dmitry Torokhov <dtor@chromium.org>
Cc: "Xu, Terrence" <terrence.xu@intel.com>
Cc: "Gao, Fred" <fred.gao@intel.com>
Acked-by: Colin Xu <colin.xu@gmail.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: https://lore.kernel.org/r/20211125051328.3359902-1-zhenyuw@linux.intel.com
[aw: line wrap]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
drivers/vfio/pci/vfio_pci_igd.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci_igd.c b/drivers/vfio/pci/vfio_pci_igd.c
index 56cd551e0e04..362f91ec8845 100644
--- a/drivers/vfio/pci/vfio_pci_igd.c
+++ b/drivers/vfio/pci/vfio_pci_igd.c
@@ -98,7 +98,8 @@ static ssize_t vfio_pci_igd_rw(struct vfio_pci_core_device *vdev,
version = cpu_to_le16(0x0201);
if (igd_opregion_shift_copy(buf, &off,
- &version + (pos - OPREGION_VERSION),
+ (u8 *)&version +
+ (pos - OPREGION_VERSION),
&pos, &remaining, bytes))
return -EFAULT;
}
@@ -121,7 +122,7 @@ static ssize_t vfio_pci_igd_rw(struct vfio_pci_core_device *vdev,
OPREGION_SIZE : 0);
if (igd_opregion_shift_copy(buf, &off,
- &rvda + (pos - OPREGION_RVDA),
+ (u8 *)&rvda + (pos - OPREGION_RVDA),
&pos, &remaining, bytes))
return -EFAULT;
}