qemu: Backport fix CVE-2023-6693

Upstream-Status: Backport [https://gitlab.com/qemu-project/qemu/-/commit/2220e8189fb94068dbad333228659fbac819abb0]

(From OE-Core rev: e993720fc31dbf94bed138b76ce33cbcd61ab9a5)

Signed-off-by: Vivek Kumbhar <vkumbhar@mvista.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 75 insertions, 0 deletions

diff --git a/meta/recipes-devtools/qemu/qemu.inc b/meta/recipes-devtools/qemu/qemu.inc
index 18752af274..d3e6ced988 100644
--- a/meta/recipes-devtools/qemu/qemu.inc
+++ b/meta/recipes-devtools/qemu/qemu.inc
@@ -104,6 +104,7 @@ SRC_URI = "https://download.qemu.org/${BPN}-${PV}.tar.xz \
            file://CVE-2023-1544.patch \
            file://CVE-2023-5088.patch \
            file://CVE-2024-24474.patch \
+           file://CVE-2023-6693.patch \
            "
 UPSTREAM_CHECK_REGEX = "qemu-(?P<pver>\d+(\.\d+)+)\.tar"
 
diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2023-6693.patch b/meta/recipes-devtools/qemu/qemu/CVE-2023-6693.patch
new file mode 100644
index 0000000000..b91f2e6902
--- /dev/null
+++ b/meta/recipes-devtools/qemu/qemu/CVE-2023-6693.patch
@@ -0,0 +1,74 @@
+From 2220e8189fb94068dbad333228659fbac819abb0 Mon Sep 17 00:00:00 2001
+From: Jason Wang <jasowang@redhat.com>
+Date: Tue, 2 Jan 2024 11:29:01 +0800
+Subject: [PATCH] virtio-net: correctly copy vnet header when flushing TX
+
+When HASH_REPORT is negotiated, the guest_hdr_len might be larger than
+the size of the mergeable rx buffer header. Using
+virtio_net_hdr_mrg_rxbuf during the header swap might lead a stack
+overflow in this case. Fixing this by using virtio_net_hdr_v1_hash
+instead.
+
+Reported-by: Xiao Lei <leixiao.nop@zju.edu.cn>
+Cc: Yuri Benditovich <yuri.benditovich@daynix.com>
+Cc: qemu-stable@nongnu.org
+Cc: Mauro Matteo Cascella <mcascell@redhat.com>
+Fixes: CVE-2023-6693
+Fixes: e22f0603fb2f ("virtio-net: reference implementation of hash report")
+Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
+Signed-off-by: Jason Wang <jasowang@redhat.com>
+
+Upstream-Status: Backport [https://gitlab.com/qemu-project/qemu/-/commit/2220e8189fb94068dbad333228659fbac819abb0]
+CVE: CVE-2023-6693
+Signed-off-by: Vivek Kumbhar <vkumbhar@mvista.com>
+---
+ hw/net/virtio-net.c | 13 +++++++++----
+ 1 file changed, 9 insertions(+), 4 deletions(-)
+
+diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
+index e1f474883..42e66697f 100644
+--- a/hw/net/virtio-net.c
++++ b/hw/net/virtio-net.c
+@@ -600,6 +600,11 @@ static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs,
+
+     n->mergeable_rx_bufs = mergeable_rx_bufs;
+
++    /*
++     * Note: when extending the vnet header, please make sure to
++     * change the vnet header copying logic in virtio_net_flush_tx()
++     * as well.
++     */
+     if (version_1) {
+         n->guest_hdr_len = hash_report ?
+             sizeof(struct virtio_net_hdr_v1_hash) :
+@@ -2520,7 +2525,7 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
+         ssize_t ret;
+         unsigned int out_num;
+         struct iovec sg[VIRTQUEUE_MAX_SIZE], sg2[VIRTQUEUE_MAX_SIZE + 1], *out_sg;
+-        struct virtio_net_hdr_mrg_rxbuf mhdr;
++        struct virtio_net_hdr_v1_hash vhdr;
+
+         elem = virtqueue_pop(q->tx_vq, sizeof(VirtQueueElement));
+         if (!elem) {
+@@ -2537,7 +2542,7 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
+         }
+
+         if (n->has_vnet_hdr) {
+-            if (iov_to_buf(out_sg, out_num, 0, &mhdr, n->guest_hdr_len) <
++            if (iov_to_buf(out_sg, out_num, 0, &vhdr, n->guest_hdr_len) <
+                 n->guest_hdr_len) {
+                 virtio_error(vdev, "virtio-net header incorrect");
+                 virtqueue_detach_element(q->tx_vq, elem, 0);
+@@ -2545,8 +2550,8 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q)
+                 return -EINVAL;
+             }
+             if (n->needs_vnet_hdr_swap) {
+-                virtio_net_hdr_swap(vdev, (void *) &mhdr);
+-                sg2[0].iov_base = &mhdr;
++                virtio_net_hdr_swap(vdev, (void *) &vhdr);
++                sg2[0].iov_base = &vhdr;
+                 sg2[0].iov_len = n->guest_hdr_len;
+                 out_num = iov_copy(&sg2[1], ARRAY_SIZE(sg2) - 1,
+                                    out_sg, out_num,
+--
+2.34.1