5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Alex Williamson <alex.williamson@xxxxxxxxxx>
commit ce9ff21ea89d191e477a02ad7eabf4f996b80a69 upstream.
count and offset are passed from user space and not checked, only
offset is capped to 40 bits, which can be used to read/write out of
bounds of the device.
Fixes: 6e3f26456009 (“vfio/platform: read and write support for the device fd”)
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Mostafa Saleh <smostafa@xxxxxxxxxx>
Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx>
Reviewed-by: Mostafa Saleh <smostafa@xxxxxxxxxx>
Tested-by: Mostafa Saleh <smostafa@xxxxxxxxxx>
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/vfio/platform/vfio_platform_common.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -405,6 +405,11 @@ static ssize_t vfio_platform_read_mmio(s
{
unsigned int done = 0;
+ if (off >= reg->size)
+ return -EINVAL;
+
+ count = min_t(size_t, count, reg->size - off);
+
if (!reg->ioaddr) {
reg->ioaddr =
ioremap_nocache(reg->addr, reg->size);
@@ -482,6 +487,11 @@ static ssize_t vfio_platform_write_mmio(
{
unsigned int done = 0;
+ if (off >= reg->size)
+ return -EINVAL;
+
+ count = min_t(size_t, count, reg->size - off);
+
if (!reg->ioaddr) {
reg->ioaddr =
ioremap_nocache(reg->addr, reg->size);
