qemu: fix CVE-2023-0330

A vulnerability in the lsi53c895a device affects the latest version
of qemu. A DMA-MMIO reentrancy problem may lead to memory corruption
bugs like stack overflow or use-after-free.

References:
https://nvd.nist.gov/vuln/detail/CVE-2023-0330

Upstream patches:
https://gitlab.com/qemu-project/qemu/-/commit/b987718bbb1d0eabf95499b976212dd5f0120d75

(From OE-Core rev: 3be283237a9e473112430bcb614b25b7ff7e64b2)

Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 76 insertions, 0 deletions

diff --git a/meta/recipes-devtools/qemu/qemu.inc b/meta/recipes-devtools/qemu/qemu.inc
index 4c9be91cb0..15eba6163f 100644
--- a/meta/recipes-devtools/qemu/qemu.inc
+++ b/meta/recipes-devtools/qemu/qemu.inc
@@ -36,6 +36,7 @@ SRC_URI = "https://download.qemu.org/${BPN}-${PV}.tar.xz \
            file://qemu-guest-agent.init \
            file://qemu-guest-agent.udev \
            file://ppc.patch \
+           file://CVE-2023-0330.patch \
            "
 UPSTREAM_CHECK_REGEX = "qemu-(?P<pver>\d+(\.\d+)+)\.tar"
 
diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2023-0330.patch b/meta/recipes-devtools/qemu/qemu/CVE-2023-0330.patch
new file mode 100644
index 0000000000..f609ea29b4
--- /dev/null
+++ b/meta/recipes-devtools/qemu/qemu/CVE-2023-0330.patch
@@ -0,0 +1,75 @@
+From b987718bbb1d0eabf95499b976212dd5f0120d75 Mon Sep 17 00:00:00 2001
+From: Thomas Huth <thuth@redhat.com>
+Date: Mon, 22 May 2023 11:10:11 +0200
+Subject: [PATCH] hw/scsi/lsi53c895a: Fix reentrancy issues in the LSI
+ controller (CVE-2023-0330)
+
+We cannot use the generic reentrancy guard in the LSI code, so
+we have to manually prevent endless reentrancy here. The problematic
+lsi_execute_script() function has already a way to detect whether
+too many instructions have been executed - we just have to slightly
+change the logic here that it also takes into account if the function
+has been called too often in a reentrant way.
+
+The code in fuzz-lsi53c895a-test.c has been taken from an earlier
+patch by Mauro Matteo Cascella.
+
+Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1563
+Message-Id: <20230522091011.1082574-1-thuth@redhat.com>
+Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
+Reviewed-by: Alexander Bulekov <alxndr@bu.edu>
+Signed-off-by: Thomas Huth <thuth@redhat.com>
+
+Upstream-Status: Backport [https://gitlab.com/qemu-project/qemu/-/commit/b987718bbb1d0eabf95499b976212dd5f0120d75]
+CVE: CVE-2023-0330
+
+Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
+---
+ hw/scsi/lsi53c895a.c               | 23 +++++++++++++++------
+ tests/qtest/fuzz-lsi53c895a-test.c | 33 ++++++++++++++++++++++++++++++
+ 2 files changed, 50 insertions(+), 6 deletions(-)
+
+diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c
+index 048436352b7a..f7d45b0b20fb 100644
+--- a/hw/scsi/lsi53c895a.c
++++ b/hw/scsi/lsi53c895a.c
+@@ -1134,15 +1134,24 @@ static void lsi_execute_script(LSIState *s)
+     uint32_t addr, addr_high;
+     int opcode;
+     int insn_processed = 0;
++    static int reentrancy_level;
++
++    reentrancy_level++;
+
+     s->istat1 |= LSI_ISTAT1_SRUN;
+ again:
+-    if (++insn_processed > LSI_MAX_INSN) {
+-        /* Some windows drivers make the device spin waiting for a memory
+-           location to change.  If we have been executed a lot of code then
+-           assume this is the case and force an unexpected device disconnect.
+-           This is apparently sufficient to beat the drivers into submission.
+-         */
++    /*
++     * Some windows drivers make the device spin waiting for a memory location
++     * to change. If we have executed more than LSI_MAX_INSN instructions then
++     * assume this is the case and force an unexpected device disconnect. This
++     * is apparently sufficient to beat the drivers into submission.
++     *
++     * Another issue (CVE-2023-0330) can occur if the script is programmed to
++     * trigger itself again and again. Avoid this problem by stopping after
++     * being called multiple times in a reentrant way (8 is an arbitrary value
++     * which should be enough for all valid use cases).
++     */
++    if (++insn_processed > LSI_MAX_INSN || reentrancy_level > 8) {
+         if (!(s->sien0 & LSI_SIST0_UDC)) {
+             qemu_log_mask(LOG_GUEST_ERROR,
+                           "lsi_scsi: inf. loop with UDC masked");
+@@ -1596,6 +1605,8 @@ static void lsi_execute_script(LSIState *s)
+         }
+     }
+     trace_lsi_execute_script_stop();
++
++    reentrancy_level--;
+ }
+
+ static uint8_t lsi_reg_readb(LSIState *s, int offset)