From: "Christian A. Ehrhardt" <l...@c--e.de>
- 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>
Signed-off-by: Christian A. Ehrhardt <l...@c--e.de>
Message-Id: <20221024154233.1043347-1...@c--e.de>
Fixes: https://gitlab.com/qemu-project/qemu/-/issues/1268
Reviewed-by: Alexander Bulekov <alx...@bu.edu>
Reviewed-by: Eric DeVolder <eric.devol...@oracle.com>
Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
---
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;
--
MST
