qemu: backport the fix for CVE-2022-3165

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 59 insertions, 0 deletions

diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2022-3165.patch b/meta/recipes-devtools/qemu/qemu/CVE-2022-3165.patch
new file mode 100644
index 0000000000..3b4a6694c2
--- /dev/null
+++ b/meta/recipes-devtools/qemu/qemu/CVE-2022-3165.patch
@@ -0,0 +1,59 @@
+CVE: CVE-2022-3165
+Upstream-Status: Backport
+Signed-off-by: Ross Burton <ross.burton@arm.com>
+
+From d307040b18bfcb1393b910f1bae753d5c12a4dc7 Mon Sep 17 00:00:00 2001
+From: Mauro Matteo Cascella <mcascell@redhat.com>
+Date: Sun, 25 Sep 2022 22:45:11 +0200
+Subject: [PATCH] ui/vnc-clipboard: fix integer underflow in
+ vnc_client_cut_text_ext
+
+Extended ClientCutText messages start with a 4-byte header. If len < 4,
+an integer underflow occurs in vnc_client_cut_text_ext. The result is
+used to decompress data in a while loop in inflate_buffer, leading to
+CPU consumption and denial of service. Prevent this by checking dlen in
+protocol_client_msg.
+
+Fixes: CVE-2022-3165
+Fixes: 0bf41cab93e5 ("ui/vnc: clipboard support")
+Reported-by: TangPeng <tangpeng@qianxin.com>
+Signed-off-by: Mauro Matteo Cascella <mcascell@redhat.com>
+Message-Id: <20220925204511.1103214-1-mcascell@redhat.com>
+Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
+---
+ ui/vnc.c | 11 ++++++++---
+ 1 file changed, 8 insertions(+), 3 deletions(-)
+
+diff --git a/ui/vnc.c b/ui/vnc.c
+index 6a05d06147..acb3629cd8 100644
+--- a/ui/vnc.c
++++ b/ui/vnc.c
+@@ -2442,8 +2442,8 @@ static int protocol_client_msg(VncState *vs, uint8_t *data, size_t len)
+         if (len == 1) {
+             return 8;
+         }
++        uint32_t dlen = abs(read_s32(data, 4));
+         if (len == 8) {
+-            uint32_t dlen = abs(read_s32(data, 4));
+             if (dlen > (1 << 20)) {
+                 error_report("vnc: client_cut_text msg payload has %u bytes"
+                              " which exceeds our limit of 1MB.", dlen);
+@@ -2456,8 +2456,13 @@ static int protocol_client_msg(VncState *vs, uint8_t *data, size_t len)
+         }
+ 
+         if (read_s32(data, 4) < 0) {
+-            vnc_client_cut_text_ext(vs, abs(read_s32(data, 4)),
+-                                    read_u32(data, 8), data + 12);
++            if (dlen < 4) {
++                error_report("vnc: malformed payload (header less than 4 bytes)"
++                             " in extended clipboard pseudo-encoding.");
++                vnc_client_error(vs);
++                break;
++            }
++            vnc_client_cut_text_ext(vs, dlen, read_u32(data, 8), data + 12);
+             break;
+         }
+         vnc_client_cut_text(vs, read_u32(data, 4), data + 8);
+-- 
+GitLab
+