File hw-acpi-erst.c-Fix-memory-handling-issue.patch of Package qemu

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File hw-acpi-erst.c-Fix-memory-handling-issue.patch of Package qemu (Revision 87028dc3f1fdd8ac2176d2121ee6cf96)

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From: "Christian A. Ehrhardt" <lk@c--e.de>
Date: Mon, 24 Oct 2022 17:42:33 +0200
Subject: hw/acpi/erst.c: Fix memory handling issues

- 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.devolder@oracle.com
Cc: Alexander Bulekov <alxndr@bu.edu>
Cc: qemu-stable@nongnu.org
Fixes: f7e26ffa590 ("ACPI ERST: support for ACPI ERST feature")
Tested-by: Alexander Bulekov <alxndr@bu.edu>
Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
Message-Id: <20221024154233.1043347-1-lk@c--e.de>
Fixes: https://gitlab.com/qemu-project/qemu/-/issues/1268
Reviewed-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit defb70980f6bed36100b74e84220f1764c0dd544)
Resolves: bsc#1205847
Signed-off-by: Dario Faggioli <dfaggioli@suse.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 df856b2669a6c198d0019b846e03..aefcc03ad6b68f2b3de7dfebf609 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;

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File hw-acpi-erst.c-Fix-memory-handling-issue.patch of Package qemu (Revision 87028dc3f1fdd8ac2176d2121ee6cf96)

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