On 221024 1224, Alexander Bulekov wrote:
> On 221024 1742, Christian A. Ehrhardt wrote:
> > - Fix memset argument order: The second argument is
> > the value, the length goes last.
> > - Fix an integer overflow reported by Alexander Bulekov.
> >
> > Both issues allow the guest to overrun the host buffer
> > allocated for the ERST memory device.
> >
> > Cc: Eric DeVolder <eric.devol...@oracle.com
> > Cc: Alexander Bulekov <alx...@bu.edu>
> > Cc: qemu-sta...@nongnu.org
> > Fixes: f7e26ffa590 ("ACPI ERST: support for ACPI ERST feature")
> > Tested-by: Alexander Bulekov <alx...@bu.edu>
>
Also:
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1268
> Reviewed-by: Alexander Bulekov <alx...@bu.edu>
>
> > Signed-off-by: Christian A. Ehrhardt <l...@c--e.de>
> > ---
> > hw/acpi/erst.c | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/hw/acpi/erst.c b/hw/acpi/erst.c
> > index df856b2669..aefcc03ad6 100644
> > --- a/hw/acpi/erst.c
> > +++ b/hw/acpi/erst.c
> > @@ -635,7 +635,7 @@ static unsigned read_erst_record(ERSTDeviceState *s)
> > if (record_length < UEFI_CPER_RECORD_MIN_SIZE) {
> > rc = STATUS_FAILED;
> > }
> > - if ((s->record_offset + record_length) > exchange_length) {
> > + if (record_length > exchange_length - s->record_offset) {
> > rc = STATUS_FAILED;
> > }
> > /* If all is ok, copy the record to the exchange buffer */
> > @@ -684,7 +684,7 @@ static unsigned write_erst_record(ERSTDeviceState *s)
> > if (record_length < UEFI_CPER_RECORD_MIN_SIZE) {
> > return STATUS_FAILED;
> > }
> > - if ((s->record_offset + record_length) > exchange_length) {
> > + if (record_length > exchange_length - s->record_offset) {
> > return STATUS_FAILED;
> > }
> >
> > @@ -716,7 +716,7 @@ static unsigned write_erst_record(ERSTDeviceState *s)
> > if (nvram) {
> > /* Write the record into the slot */
> > memcpy(nvram, exchange, record_length);
> > - memset(nvram + record_length, exchange_length - record_length,
> > 0xFF);
> > + memset(nvram + record_length, 0xFF, exchange_length -
> > record_length);
> > /* If a new record, increment the record_count */
> > if (!record_found) {
> > uint32_t record_count;
> > --
> > 2.34.1
> >
> >
