qemu: fix CVE-2019-20382

(From OE-Core rev: dac4545cdf0ab848086da96eac123d0c640cd8b2)

Signed-off-by: Lee Chee Yang <chee.yang.lee@intel.com>
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 1019 insertions, 0 deletions

diff --git a/meta/recipes-devtools/qemu/qemu.inc b/meta/recipes-devtools/qemu/qemu.inc
index d394db8a41..f451017f6d 100644
--- a/meta/recipes-devtools/qemu/qemu.inc
+++ b/meta/recipes-devtools/qemu/qemu.inc
@@ -30,6 +30,7 @@ SRC_URI = "https://download.qemu.org/${BPN}-${PV}.tar.xz \
            file://CVE-2019-15890.patch \
            file://CVE-2019-12068.patch \
            file://CVE-2020-1711.patch \
+           file://CVE-2019-20382.patch \
            "
 UPSTREAM_CHECK_REGEX = "qemu-(?P<pver>\d+(\.\d+)+)\.tar"
 
diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2019-20382.patch b/meta/recipes-devtools/qemu/qemu/CVE-2019-20382.patch
new file mode 100644
index 0000000000..183d100398
--- /dev/null
+++ b/meta/recipes-devtools/qemu/qemu/CVE-2019-20382.patch
@@ -0,0 +1,1018 @@
+From 6bf21f3d83e95bcc4ba35a7a07cc6655e8b010b0 Mon Sep 17 00:00:00 2001
+From: Li Qiang <liq3ea@163.com>
+Date: Sat, 31 Aug 2019 08:39:22 -0700
+Subject: [PATCH] vnc: fix memory leak when vnc disconnect
+
+Currently when qemu receives a vnc connect, it creates a 'VncState' to
+represent this connection. In 'vnc_worker_thread_loop' it creates a
+local 'VncState'. The connection 'VcnState' and local 'VncState' exchange
+data in 'vnc_async_encoding_start' and 'vnc_async_encoding_end'.
+In 'zrle_compress_data' it calls 'deflateInit2' to allocate the libz library
+opaque data. The 'VncState' used in 'zrle_compress_data' is the local
+'VncState'. In 'vnc_zrle_clear' it calls 'deflateEnd' to free the libz
+library opaque data. The 'VncState' used in 'vnc_zrle_clear' is the connection
+'VncState'. In currently implementation there will be a memory leak when the
+vnc disconnect. Following is the asan output backtrack:
+
+Direct leak of 29760 byte(s) in 5 object(s) allocated from:
+    0 0xffffa67ef3c3 in __interceptor_calloc (/lib64/libasan.so.4+0xd33c3)
+    1 0xffffa65071cb in g_malloc0 (/lib64/libglib-2.0.so.0+0x571cb)
+    2 0xffffa5e968f7 in deflateInit2_ (/lib64/libz.so.1+0x78f7)
+    3 0xaaaacec58613 in zrle_compress_data ui/vnc-enc-zrle.c:87
+    4 0xaaaacec58613 in zrle_send_framebuffer_update ui/vnc-enc-zrle.c:344
+    5 0xaaaacec34e77 in vnc_send_framebuffer_update ui/vnc.c:919
+    6 0xaaaacec5e023 in vnc_worker_thread_loop ui/vnc-jobs.c:271
+    7 0xaaaacec5e5e7 in vnc_worker_thread ui/vnc-jobs.c:340
+    8 0xaaaacee4d3c3 in qemu_thread_start util/qemu-thread-posix.c:502
+    9 0xffffa544e8bb in start_thread (/lib64/libpthread.so.0+0x78bb)
+    10 0xffffa53965cb in thread_start (/lib64/libc.so.6+0xd55cb)
+
+This is because the opaque allocated in 'deflateInit2' is not freed in
+'deflateEnd'. The reason is that the 'deflateEnd' calls 'deflateStateCheck'
+and in the latter will check whether 's->strm != strm'(libz's data structure).
+This check will be true so in 'deflateEnd' it just return 'Z_STREAM_ERROR' and
+not free the data allocated in 'deflateInit2'.
+
+The reason this happens is that the 'VncState' contains the whole 'VncZrle',
+so when calling 'deflateInit2', the 's->strm' will be the local address.
+So 's->strm != strm' will be true.
+
+To fix this issue, we need to make 'zrle' of 'VncState' to be a pointer.
+Then the connection 'VncState' and local 'VncState' exchange mechanism will
+work as expection. The 'tight' of 'VncState' has the same issue, let's also turn
+it to a pointer.
+
+Reported-by: Ying Fang <fangying1@huawei.com>
+Signed-off-by: Li Qiang <liq3ea@163.com>
+Message-id: 20190831153922.121308-1-liq3ea@163.com
+Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
+
+Upstream-Status: Backport [https://git.qemu.org/?p=qemu.git;a=commit;h=6bf21f3d83e95bcc4ba35a7a07cc6655e8b010b0]
+CVE: CVE-2019-20382
+Signed-off-by: Lee Chee Yang <chee.yang.lee@intel.com>
+
+---
+ ui/vnc-enc-tight.c    | 219 +++++++++++++++++++++++++-------------------------
+ ui/vnc-enc-zlib.c     |  11 +--
+ ui/vnc-enc-zrle.c     |  68 ++++++++--------
+ ui/vnc-enc-zrle.inc.c |   2 +-
+ ui/vnc.c              |  28 ++++---
+ ui/vnc.h              |   4 +-
+ 6 files changed, 170 insertions(+), 162 deletions(-)
+
+diff --git a/ui/vnc-enc-tight.c b/ui/vnc-enc-tight.c
+index 9084c22..1e08518 100644
+--- a/ui/vnc-enc-tight.c
++++ b/ui/vnc-enc-tight.c
+@@ -116,7 +116,7 @@ static int send_png_rect(VncState *vs, int x, int y, int w, int h,
+ 
+ static bool tight_can_send_png_rect(VncState *vs, int w, int h)
+ {
+-    if (vs->tight.type != VNC_ENCODING_TIGHT_PNG) {
++    if (vs->tight->type != VNC_ENCODING_TIGHT_PNG) {
+         return false;
+     }
+ 
+@@ -144,7 +144,7 @@ tight_detect_smooth_image24(VncState *vs, int w, int h)
+     int pixels = 0;
+     int pix, left[3];
+     unsigned int errors;
+-    unsigned char *buf = vs->tight.tight.buffer;
++    unsigned char *buf = vs->tight->tight.buffer;
+ 
+     /*
+      * If client is big-endian, color samples begin from the second
+@@ -215,7 +215,7 @@ tight_detect_smooth_image24(VncState *vs, int w, int h)
+         int pixels = 0;                                                 \
+         int sample, sum, left[3];                                       \
+         unsigned int errors;                                            \
+-        unsigned char *buf = vs->tight.tight.buffer;                    \
++        unsigned char *buf = vs->tight->tight.buffer;                    \
+                                                                         \
+         endian = 0; /* FIXME */                                         \
+                                                                         \
+@@ -296,8 +296,8 @@ static int
+ tight_detect_smooth_image(VncState *vs, int w, int h)
+ {
+     unsigned int errors;
+-    int compression = vs->tight.compression;
+-    int quality = vs->tight.quality;
++    int compression = vs->tight->compression;
++    int quality = vs->tight->quality;
+ 
+     if (!vs->vd->lossy) {
+         return 0;
+@@ -309,7 +309,7 @@ tight_detect_smooth_image(VncState *vs, int w, int h)
+         return 0;
+     }
+ 
+-    if (vs->tight.quality != (uint8_t)-1) {
++    if (vs->tight->quality != (uint8_t)-1) {
+         if (w * h < VNC_TIGHT_JPEG_MIN_RECT_SIZE) {
+             return 0;
+         }
+@@ -320,9 +320,9 @@ tight_detect_smooth_image(VncState *vs, int w, int h)
+     }
+ 
+     if (vs->client_pf.bytes_per_pixel == 4) {
+-        if (vs->tight.pixel24) {
++        if (vs->tight->pixel24) {
+             errors = tight_detect_smooth_image24(vs, w, h);
+-            if (vs->tight.quality != (uint8_t)-1) {
++            if (vs->tight->quality != (uint8_t)-1) {
+                 return (errors < tight_conf[quality].jpeg_threshold24);
+             }
+             return (errors < tight_conf[compression].gradient_threshold24);
+@@ -352,7 +352,7 @@ tight_detect_smooth_image(VncState *vs, int w, int h)
+         uint##bpp##_t c0, c1, ci;                                       \
+         int i, n0, n1;                                                  \
+                                                                         \
+-        data = (uint##bpp##_t *)vs->tight.tight.buffer;                 \
++        data = (uint##bpp##_t *)vs->tight->tight.buffer;                \
+                                                                         \
+         c0 = data[0];                                                   \
+         i = 1;                                                          \
+@@ -423,9 +423,9 @@ static int tight_fill_palette(VncState *vs, int x, int y,
+ {
+     int max;
+ 
+-    max = count / tight_conf[vs->tight.compression].idx_max_colors_divisor;
++    max = count / tight_conf[vs->tight->compression].idx_max_colors_divisor;
+     if (max < 2 &&
+-        count >= tight_conf[vs->tight.compression].mono_min_rect_size) {
++        count >= tight_conf[vs->tight->compression].mono_min_rect_size) {
+         max = 2;
+     }
+     if (max >= 256) {
+@@ -558,7 +558,7 @@ tight_filter_gradient24(VncState *vs, uint8_t *buf, int w, int h)
+     int x, y, c;
+ 
+     buf32 = (uint32_t *)buf;
+-    memset(vs->tight.gradient.buffer, 0, w * 3 * sizeof(int));
++    memset(vs->tight->gradient.buffer, 0, w * 3 * sizeof(int));
+ 
+     if (1 /* FIXME */) {
+         shift[0] = vs->client_pf.rshift;
+@@ -575,7 +575,7 @@ tight_filter_gradient24(VncState *vs, uint8_t *buf, int w, int h)
+             upper[c] = 0;
+             here[c] = 0;
+         }
+-        prev = (int *)vs->tight.gradient.buffer;
++        prev = (int *)vs->tight->gradient.buffer;
+         for (x = 0; x < w; x++) {
+             pix32 = *buf32++;
+             for (c = 0; c < 3; c++) {
+@@ -615,7 +615,7 @@ tight_filter_gradient24(VncState *vs, uint8_t *buf, int w, int h)
+         int prediction;                                                 \
+         int x, y, c;                                                    \
+                                                                         \
+-        memset (vs->tight.gradient.buffer, 0, w * 3 * sizeof(int));     \
++        memset(vs->tight->gradient.buffer, 0, w * 3 * sizeof(int));     \
+                                                                         \
+         endian = 0; /* FIXME */                                         \
+                                                                         \
+@@ -631,7 +631,7 @@ tight_filter_gradient24(VncState *vs, uint8_t *buf, int w, int h)
+                 upper[c] = 0;                                           \
+                 here[c] = 0;                                            \
+             }                                                           \
+-            prev = (int *)vs->tight.gradient.buffer;                    \
++            prev = (int *)vs->tight->gradient.buffer;                    \
+             for (x = 0; x < w; x++) {                                   \
+                 pix = *buf;                                             \
+                 if (endian) {                                           \
+@@ -785,7 +785,7 @@ static void extend_solid_area(VncState *vs, int x, int y, int w, int h,
+ static int tight_init_stream(VncState *vs, int stream_id,
+                              int level, int strategy)
+ {
+-    z_streamp zstream = &vs->tight.stream[stream_id];
++    z_streamp zstream = &vs->tight->stream[stream_id];
+ 
+     if (zstream->opaque == NULL) {
+         int err;
+@@ -803,15 +803,15 @@ static int tight_init_stream(VncState *vs, int stream_id,
+             return -1;
+         }
+ 
+-        vs->tight.levels[stream_id] = level;
++        vs->tight->levels[stream_id] = level;
+         zstream->opaque = vs;
+     }
+ 
+-    if (vs->tight.levels[stream_id] != level) {
++    if (vs->tight->levels[stream_id] != level) {
+         if (deflateParams(zstream, level, strategy) != Z_OK) {
+             return -1;
+         }
+-        vs->tight.levels[stream_id] = level;
++        vs->tight->levels[stream_id] = level;
+     }
+     return 0;
+ }
+@@ -839,11 +839,11 @@ static void tight_send_compact_size(VncState *vs, size_t len)
+ static int tight_compress_data(VncState *vs, int stream_id, size_t bytes,
+                                int level, int strategy)
+ {
+-    z_streamp zstream = &vs->tight.stream[stream_id];
++    z_streamp zstream = &vs->tight->stream[stream_id];
+     int previous_out;
+ 
+     if (bytes < VNC_TIGHT_MIN_TO_COMPRESS) {
+-        vnc_write(vs, vs->tight.tight.buffer, vs->tight.tight.offset);
++        vnc_write(vs, vs->tight->tight.buffer, vs->tight->tight.offset);
+         return bytes;
+     }
+ 
+@@ -852,13 +852,13 @@ static int tight_compress_data(VncState *vs, int stream_id, size_t bytes,
+     }
+ 
+     /* reserve memory in output buffer */
+-    buffer_reserve(&vs->tight.zlib, bytes + 64);
++    buffer_reserve(&vs->tight->zlib, bytes + 64);
+ 
+     /* set pointers */
+-    zstream->next_in = vs->tight.tight.buffer;
+-    zstream->avail_in = vs->tight.tight.offset;
+-    zstream->next_out = vs->tight.zlib.buffer + vs->tight.zlib.offset;
+-    zstream->avail_out = vs->tight.zlib.capacity - vs->tight.zlib.offset;
++    zstream->next_in = vs->tight->tight.buffer;
++    zstream->avail_in = vs->tight->tight.offset;
++    zstream->next_out = vs->tight->zlib.buffer + vs->tight->zlib.offset;
++    zstream->avail_out = vs->tight->zlib.capacity - vs->tight->zlib.offset;
+     previous_out = zstream->avail_out;
+     zstream->data_type = Z_BINARY;
+ 
+@@ -868,14 +868,14 @@ static int tight_compress_data(VncState *vs, int stream_id, size_t bytes,
+         return -1;
+     }
+ 
+-    vs->tight.zlib.offset = vs->tight.zlib.capacity - zstream->avail_out;
++    vs->tight->zlib.offset = vs->tight->zlib.capacity - zstream->avail_out;
+     /* ...how much data has actually been produced by deflate() */
+     bytes = previous_out - zstream->avail_out;
+ 
+     tight_send_compact_size(vs, bytes);
+-    vnc_write(vs, vs->tight.zlib.buffer, bytes);
++    vnc_write(vs, vs->tight->zlib.buffer, bytes);
+ 
+-    buffer_reset(&vs->tight.zlib);
++    buffer_reset(&vs->tight->zlib);
+ 
+     return bytes;
+ }
+@@ -927,16 +927,17 @@ static int send_full_color_rect(VncState *vs, int x, int y, int w, int h)
+ 
+     vnc_write_u8(vs, stream << 4); /* no flushing, no filter */
+ 
+-    if (vs->tight.pixel24) {
+-        tight_pack24(vs, vs->tight.tight.buffer, w * h, &vs->tight.tight.offset);
++    if (vs->tight->pixel24) {
++        tight_pack24(vs, vs->tight->tight.buffer, w * h,
++                     &vs->tight->tight.offset);
+         bytes = 3;
+     } else {
+         bytes = vs->client_pf.bytes_per_pixel;
+     }
+ 
+     bytes = tight_compress_data(vs, stream, w * h * bytes,
+-                                tight_conf[vs->tight.compression].raw_zlib_level,
+-                                Z_DEFAULT_STRATEGY);
++                            tight_conf[vs->tight->compression].raw_zlib_level,
++                            Z_DEFAULT_STRATEGY);
+ 
+     return (bytes >= 0);
+ }
+@@ -947,14 +948,14 @@ static int send_solid_rect(VncState *vs)
+ 
+     vnc_write_u8(vs, VNC_TIGHT_FILL << 4); /* no flushing, no filter */
+ 
+-    if (vs->tight.pixel24) {
+-        tight_pack24(vs, vs->tight.tight.buffer, 1, &vs->tight.tight.offset);
++    if (vs->tight->pixel24) {
++        tight_pack24(vs, vs->tight->tight.buffer, 1, &vs->tight->tight.offset);
+         bytes = 3;
+     } else {
+         bytes = vs->client_pf.bytes_per_pixel;
+     }
+ 
+-    vnc_write(vs, vs->tight.tight.buffer, bytes);
++    vnc_write(vs, vs->tight->tight.buffer, bytes);
+     return 1;
+ }
+ 
+@@ -963,7 +964,7 @@ static int send_mono_rect(VncState *vs, int x, int y,
+ {
+     ssize_t bytes;
+     int stream = 1;
+-    int level = tight_conf[vs->tight.compression].mono_zlib_level;
++    int level = tight_conf[vs->tight->compression].mono_zlib_level;
+ 
+ #ifdef CONFIG_VNC_PNG
+     if (tight_can_send_png_rect(vs, w, h)) {
+@@ -991,26 +992,26 @@ static int send_mono_rect(VncState *vs, int x, int y,
+         uint32_t buf[2] = {bg, fg};
+         size_t ret = sizeof (buf);
+ 
+-        if (vs->tight.pixel24) {
++        if (vs->tight->pixel24) {
+             tight_pack24(vs, (unsigned char*)buf, 2, &ret);
+         }
+         vnc_write(vs, buf, ret);
+ 
+-        tight_encode_mono_rect32(vs->tight.tight.buffer, w, h, bg, fg);
++        tight_encode_mono_rect32(vs->tight->tight.buffer, w, h, bg, fg);
+         break;
+     }
+     case 2:
+         vnc_write(vs, &bg, 2);
+         vnc_write(vs, &fg, 2);
+-        tight_encode_mono_rect16(vs->tight.tight.buffer, w, h, bg, fg);
++        tight_encode_mono_rect16(vs->tight->tight.buffer, w, h, bg, fg);
+         break;
+     default:
+         vnc_write_u8(vs, bg);
+         vnc_write_u8(vs, fg);
+-        tight_encode_mono_rect8(vs->tight.tight.buffer, w, h, bg, fg);
++        tight_encode_mono_rect8(vs->tight->tight.buffer, w, h, bg, fg);
+         break;
+     }
+-    vs->tight.tight.offset = bytes;
++    vs->tight->tight.offset = bytes;
+ 
+     bytes = tight_compress_data(vs, stream, bytes, level, Z_DEFAULT_STRATEGY);
+     return (bytes >= 0);
+@@ -1040,7 +1041,7 @@ static void write_palette(int idx, uint32_t color, void *opaque)
+ static bool send_gradient_rect(VncState *vs, int x, int y, int w, int h)
+ {
+     int stream = 3;
+-    int level = tight_conf[vs->tight.compression].gradient_zlib_level;
++    int level = tight_conf[vs->tight->compression].gradient_zlib_level;
+     ssize_t bytes;
+ 
+     if (vs->client_pf.bytes_per_pixel == 1) {
+@@ -1050,23 +1051,23 @@ static bool send_gradient_rect(VncState *vs, int x, int y, int w, int h)
+     vnc_write_u8(vs, (stream | VNC_TIGHT_EXPLICIT_FILTER) << 4);
+     vnc_write_u8(vs, VNC_TIGHT_FILTER_GRADIENT);
+ 
+-    buffer_reserve(&vs->tight.gradient, w * 3 * sizeof (int));
++    buffer_reserve(&vs->tight->gradient, w * 3 * sizeof(int));
+ 
+-    if (vs->tight.pixel24) {
+-        tight_filter_gradient24(vs, vs->tight.tight.buffer, w, h);
++    if (vs->tight->pixel24) {
++        tight_filter_gradient24(vs, vs->tight->tight.buffer, w, h);
+         bytes = 3;
+     } else if (vs->client_pf.bytes_per_pixel == 4) {
+-        tight_filter_gradient32(vs, (uint32_t *)vs->tight.tight.buffer, w, h);
++        tight_filter_gradient32(vs, (uint32_t *)vs->tight->tight.buffer, w, h);
+         bytes = 4;
+     } else {
+-        tight_filter_gradient16(vs, (uint16_t *)vs->tight.tight.buffer, w, h);
++        tight_filter_gradient16(vs, (uint16_t *)vs->tight->tight.buffer, w, h);
+         bytes = 2;
+     }
+ 
+-    buffer_reset(&vs->tight.gradient);
++    buffer_reset(&vs->tight->gradient);
+ 
+     bytes = w * h * bytes;
+-    vs->tight.tight.offset = bytes;
++    vs->tight->tight.offset = bytes;
+ 
+     bytes = tight_compress_data(vs, stream, bytes,
+                                 level, Z_FILTERED);
+@@ -1077,7 +1078,7 @@ static int send_palette_rect(VncState *vs, int x, int y,
+                              int w, int h, VncPalette *palette)
+ {
+     int stream = 2;
+-    int level = tight_conf[vs->tight.compression].idx_zlib_level;
++    int level = tight_conf[vs->tight->compression].idx_zlib_level;
+     int colors;
+     ssize_t bytes;
+ 
+@@ -1104,12 +1105,12 @@ static int send_palette_rect(VncState *vs, int x, int y,
+         palette_iter(palette, write_palette, &priv);
+         vnc_write(vs, header, sizeof(header));
+ 
+-        if (vs->tight.pixel24) {
++        if (vs->tight->pixel24) {
+             tight_pack24(vs, vs->output.buffer + old_offset, colors, &offset);
+             vs->output.offset = old_offset + offset;
+         }
+ 
+-        tight_encode_indexed_rect32(vs->tight.tight.buffer, w * h, palette);
++        tight_encode_indexed_rect32(vs->tight->tight.buffer, w * h, palette);
+         break;
+     }
+     case 2:
+@@ -1119,7 +1120,7 @@ static int send_palette_rect(VncState *vs, int x, int y,
+ 
+         palette_iter(palette, write_palette, &priv);
+         vnc_write(vs, header, sizeof(header));
+-        tight_encode_indexed_rect16(vs->tight.tight.buffer, w * h, palette);
++        tight_encode_indexed_rect16(vs->tight->tight.buffer, w * h, palette);
+         break;
+     }
+     default:
+@@ -1127,7 +1128,7 @@ static int send_palette_rect(VncState *vs, int x, int y,
+         break;
+     }
+     bytes = w * h;
+-    vs->tight.tight.offset = bytes;
++    vs->tight->tight.offset = bytes;
+ 
+     bytes = tight_compress_data(vs, stream, bytes,
+                                 level, Z_DEFAULT_STRATEGY);
+@@ -1146,7 +1147,7 @@ static int send_palette_rect(VncState *vs, int x, int y,
+ static void jpeg_init_destination(j_compress_ptr cinfo)
+ {
+     VncState *vs = cinfo->client_data;
+-    Buffer *buffer = &vs->tight.jpeg;
++    Buffer *buffer = &vs->tight->jpeg;
+ 
+     cinfo->dest->next_output_byte = (JOCTET *)buffer->buffer + buffer->offset;
+     cinfo->dest->free_in_buffer = (size_t)(buffer->capacity - buffer->offset);
+@@ -1156,7 +1157,7 @@ static void jpeg_init_destination(j_compress_ptr cinfo)
+ static boolean jpeg_empty_output_buffer(j_compress_ptr cinfo)
+ {
+     VncState *vs = cinfo->client_data;
+-    Buffer *buffer = &vs->tight.jpeg;
++    Buffer *buffer = &vs->tight->jpeg;
+ 
+     buffer->offset = buffer->capacity;
+     buffer_reserve(buffer, 2048);
+@@ -1168,7 +1169,7 @@ static boolean jpeg_empty_output_buffer(j_compress_ptr cinfo)
+ static void jpeg_term_destination(j_compress_ptr cinfo)
+ {
+     VncState *vs = cinfo->client_data;
+-    Buffer *buffer = &vs->tight.jpeg;
++    Buffer *buffer = &vs->tight->jpeg;
+ 
+     buffer->offset = buffer->capacity - cinfo->dest->free_in_buffer;
+ }
+@@ -1187,7 +1188,7 @@ static int send_jpeg_rect(VncState *vs, int x, int y, int w, int h, int quality)
+         return send_full_color_rect(vs, x, y, w, h);
+     }
+ 
+-    buffer_reserve(&vs->tight.jpeg, 2048);
++    buffer_reserve(&vs->tight->jpeg, 2048);
+ 
+     cinfo.err = jpeg_std_error(&jerr);
+     jpeg_create_compress(&cinfo);
+@@ -1222,9 +1223,9 @@ static int send_jpeg_rect(VncState *vs, int x, int y, int w, int h, int quality)
+ 
+     vnc_write_u8(vs, VNC_TIGHT_JPEG << 4);
+ 
+-    tight_send_compact_size(vs, vs->tight.jpeg.offset);
+-    vnc_write(vs, vs->tight.jpeg.buffer, vs->tight.jpeg.offset);
+-    buffer_reset(&vs->tight.jpeg);
++    tight_send_compact_size(vs, vs->tight->jpeg.offset);
++    vnc_write(vs, vs->tight->jpeg.buffer, vs->tight->jpeg.offset);
++    buffer_reset(&vs->tight->jpeg);
+ 
+     return 1;
+ }
+@@ -1240,7 +1241,7 @@ static void write_png_palette(int idx, uint32_t pix, void *opaque)
+     VncState *vs = priv->vs;
+     png_colorp color = &priv->png_palette[idx];
+ 
+-    if (vs->tight.pixel24)
++    if (vs->tight->pixel24)
+     {
+         color->red = (pix >> vs->client_pf.rshift) & vs->client_pf.rmax;
+         color->green = (pix >> vs->client_pf.gshift) & vs->client_pf.gmax;
+@@ -1267,10 +1268,10 @@ static void png_write_data(png_structp png_ptr, png_bytep data,
+ {
+     VncState *vs = png_get_io_ptr(png_ptr);
+ 
+-    buffer_reserve(&vs->tight.png, vs->tight.png.offset + length);
+-    memcpy(vs->tight.png.buffer + vs->tight.png.offset, data, length);
++    buffer_reserve(&vs->tight->png, vs->tight->png.offset + length);
++    memcpy(vs->tight->png.buffer + vs->tight->png.offset, data, length);
+ 
+-    vs->tight.png.offset += length;
++    vs->tight->png.offset += length;
+ }
+ 
+ static void png_flush_data(png_structp png_ptr)
+@@ -1295,8 +1296,8 @@ static int send_png_rect(VncState *vs, int x, int y, int w, int h,
+     png_infop info_ptr;
+     png_colorp png_palette = NULL;
+     pixman_image_t *linebuf;
+-    int level = tight_png_conf[vs->tight.compression].png_zlib_level;
+-    int filters = tight_png_conf[vs->tight.compression].png_filters;
++    int level = tight_png_conf[vs->tight->compression].png_zlib_level;
++    int filters = tight_png_conf[vs->tight->compression].png_filters;
+     uint8_t *buf;
+     int dy;
+ 
+@@ -1340,21 +1341,23 @@ static int send_png_rect(VncState *vs, int x, int y, int w, int h,
+         png_set_PLTE(png_ptr, info_ptr, png_palette, palette_size(palette));
+ 
+         if (vs->client_pf.bytes_per_pixel == 4) {
+-            tight_encode_indexed_rect32(vs->tight.tight.buffer, w * h, palette);
++            tight_encode_indexed_rect32(vs->tight->tight.buffer, w * h,
++                                        palette);
+         } else {
+-            tight_encode_indexed_rect16(vs->tight.tight.buffer, w * h, palette);
++            tight_encode_indexed_rect16(vs->tight->tight.buffer, w * h,
++                                        palette);
+         }
+     }
+ 
+     png_write_info(png_ptr, info_ptr);
+ 
+-    buffer_reserve(&vs->tight.png, 2048);
++    buffer_reserve(&vs->tight->png, 2048);
+     linebuf = qemu_pixman_linebuf_create(PIXMAN_BE_r8g8b8, w);
+     buf = (uint8_t *)pixman_image_get_data(linebuf);
+     for (dy = 0; dy < h; dy++)
+     {
+         if (color_type == PNG_COLOR_TYPE_PALETTE) {
+-            memcpy(buf, vs->tight.tight.buffer + (dy * w), w);
++            memcpy(buf, vs->tight->tight.buffer + (dy * w), w);
+         } else {
+             qemu_pixman_linebuf_fill(linebuf, vs->vd->server, w, x, y + dy);
+         }
+@@ -1372,27 +1375,27 @@ static int send_png_rect(VncState *vs, int x, int y, int w, int h,
+ 
+     vnc_write_u8(vs, VNC_TIGHT_PNG << 4);
+ 
+-    tight_send_compact_size(vs, vs->tight.png.offset);
+-    vnc_write(vs, vs->tight.png.buffer, vs->tight.png.offset);
+-    buffer_reset(&vs->tight.png);
++    tight_send_compact_size(vs, vs->tight->png.offset);
++    vnc_write(vs, vs->tight->png.buffer, vs->tight->png.offset);
++    buffer_reset(&vs->tight->png);
+     return 1;
+ }
+ #endif /* CONFIG_VNC_PNG */
+ 
+ static void vnc_tight_start(VncState *vs)
+ {
+-    buffer_reset(&vs->tight.tight);
++    buffer_reset(&vs->tight->tight);
+ 
+     // make the output buffer be the zlib buffer, so we can compress it later
+-    vs->tight.tmp = vs->output;
+-    vs->output = vs->tight.tight;
++    vs->tight->tmp = vs->output;
++    vs->output = vs->tight->tight;
+ }
+ 
+ static void vnc_tight_stop(VncState *vs)
+ {
+     // switch back to normal output/zlib buffers
+-    vs->tight.tight = vs->output;
+-    vs->output = vs->tight.tmp;
++    vs->tight->tight = vs->output;
++    vs->output = vs->tight->tmp;
+ }
+ 
+ static int send_sub_rect_nojpeg(VncState *vs, int x, int y, int w, int h,
+@@ -1426,9 +1429,9 @@ static int send_sub_rect_jpeg(VncState *vs, int x, int y, int w, int h,
+     int ret;
+ 
+     if (colors == 0) {
+-        if (force || (tight_jpeg_conf[vs->tight.quality].jpeg_full &&
++        if (force || (tight_jpeg_conf[vs->tight->quality].jpeg_full &&
+                       tight_detect_smooth_image(vs, w, h))) {
+-            int quality = tight_conf[vs->tight.quality].jpeg_quality;
++            int quality = tight_conf[vs->tight->quality].jpeg_quality;
+ 
+             ret = send_jpeg_rect(vs, x, y, w, h, quality);
+         } else {
+@@ -1440,9 +1443,9 @@ static int send_sub_rect_jpeg(VncState *vs, int x, int y, int w, int h,
+         ret = send_mono_rect(vs, x, y, w, h, bg, fg);
+     } else if (colors <= 256) {
+         if (force || (colors > 96 &&
+-                      tight_jpeg_conf[vs->tight.quality].jpeg_idx &&
++                      tight_jpeg_conf[vs->tight->quality].jpeg_idx &&
+                       tight_detect_smooth_image(vs, w, h))) {
+-            int quality = tight_conf[vs->tight.quality].jpeg_quality;
++            int quality = tight_conf[vs->tight->quality].jpeg_quality;
+ 
+             ret = send_jpeg_rect(vs, x, y, w, h, quality);
+         } else {
+@@ -1480,20 +1483,20 @@ static int send_sub_rect(VncState *vs, int x, int y, int w, int h)
+         qemu_thread_atexit_add(&vnc_tight_cleanup_notifier);
+     }
+ 
+-    vnc_framebuffer_update(vs, x, y, w, h, vs->tight.type);
++    vnc_framebuffer_update(vs, x, y, w, h, vs->tight->type);
+ 
+     vnc_tight_start(vs);
+     vnc_raw_send_framebuffer_update(vs, x, y, w, h);
+     vnc_tight_stop(vs);
+ 
+ #ifdef CONFIG_VNC_JPEG
+-    if (!vs->vd->non_adaptive && vs->tight.quality != (uint8_t)-1) {
++    if (!vs->vd->non_adaptive && vs->tight->quality != (uint8_t)-1) {
+         double freq = vnc_update_freq(vs, x, y, w, h);
+ 
+-        if (freq < tight_jpeg_conf[vs->tight.quality].jpeg_freq_min) {
++        if (freq < tight_jpeg_conf[vs->tight->quality].jpeg_freq_min) {
+             allow_jpeg = false;
+         }
+-        if (freq >= tight_jpeg_conf[vs->tight.quality].jpeg_freq_threshold) {
++        if (freq >= tight_jpeg_conf[vs->tight->quality].jpeg_freq_threshold) {
+             force_jpeg = true;
+             vnc_sent_lossy_rect(vs, x, y, w, h);
+         }
+@@ -1503,7 +1506,7 @@ static int send_sub_rect(VncState *vs, int x, int y, int w, int h)
+     colors = tight_fill_palette(vs, x, y, w * h, &bg, &fg, color_count_palette);
+ 
+ #ifdef CONFIG_VNC_JPEG
+-    if (allow_jpeg && vs->tight.quality != (uint8_t)-1) {
++    if (allow_jpeg && vs->tight->quality != (uint8_t)-1) {
+         ret = send_sub_rect_jpeg(vs, x, y, w, h, bg, fg, colors,
+                                  color_count_palette, force_jpeg);
+     } else {
+@@ -1520,7 +1523,7 @@ static int send_sub_rect(VncState *vs, int x, int y, int w, int h)
+ 
+ static int send_sub_rect_solid(VncState *vs, int x, int y, int w, int h)
+ {
+-    vnc_framebuffer_update(vs, x, y, w, h, vs->tight.type);
++    vnc_framebuffer_update(vs, x, y, w, h, vs->tight->type);
+ 
+     vnc_tight_start(vs);
+     vnc_raw_send_framebuffer_update(vs, x, y, w, h);
+@@ -1538,8 +1541,8 @@ static int send_rect_simple(VncState *vs, int x, int y, int w, int h,
+     int rw, rh;
+     int n = 0;
+ 
+-    max_size = tight_conf[vs->tight.compression].max_rect_size;
+-    max_width = tight_conf[vs->tight.compression].max_rect_width;
++    max_size = tight_conf[vs->tight->compression].max_rect_size;
++    max_width = tight_conf[vs->tight->compression].max_rect_width;
+ 
+     if (split && (w > max_width || w * h > max_size)) {
+         max_sub_width = (w > max_width) ? max_width : w;
+@@ -1648,16 +1651,16 @@ static int tight_send_framebuffer_update(VncState *vs, int x, int y,
+ 
+     if (vs->client_pf.bytes_per_pixel == 4 && vs->client_pf.rmax == 0xFF &&
+         vs->client_pf.bmax == 0xFF && vs->client_pf.gmax == 0xFF) {
+-        vs->tight.pixel24 = true;
++        vs->tight->pixel24 = true;
+     } else {
+-        vs->tight.pixel24 = false;
++        vs->tight->pixel24 = false;
+     }
+ 
+ #ifdef CONFIG_VNC_JPEG
+-    if (vs->tight.quality != (uint8_t)-1) {
++    if (vs->tight->quality != (uint8_t)-1) {
+         double freq = vnc_update_freq(vs, x, y, w, h);
+ 
+-        if (freq > tight_jpeg_conf[vs->tight.quality].jpeg_freq_threshold) {
++        if (freq > tight_jpeg_conf[vs->tight->quality].jpeg_freq_threshold) {
+             return send_rect_simple(vs, x, y, w, h, false);
+         }
+     }
+@@ -1669,8 +1672,8 @@ static int tight_send_framebuffer_update(VncState *vs, int x, int y,
+ 
+     /* Calculate maximum number of rows in one non-solid rectangle. */
+ 
+-    max_rows = tight_conf[vs->tight.compression].max_rect_size;
+-    max_rows /= MIN(tight_conf[vs->tight.compression].max_rect_width, w);
++    max_rows = tight_conf[vs->tight->compression].max_rect_size;
++    max_rows /= MIN(tight_conf[vs->tight->compression].max_rect_width, w);
+ 
+     return find_large_solid_color_rect(vs, x, y, w, h, max_rows);
+ }
+@@ -1678,33 +1681,33 @@ static int tight_send_framebuffer_update(VncState *vs, int x, int y,
+ int vnc_tight_send_framebuffer_update(VncState *vs, int x, int y,
+                                       int w, int h)
+ {
+-    vs->tight.type = VNC_ENCODING_TIGHT;
++    vs->tight->type = VNC_ENCODING_TIGHT;
+     return tight_send_framebuffer_update(vs, x, y, w, h);
+ }
+ 
+ int vnc_tight_png_send_framebuffer_update(VncState *vs, int x, int y,
+                                           int w, int h)
+ {
+-    vs->tight.type = VNC_ENCODING_TIGHT_PNG;
++    vs->tight->type = VNC_ENCODING_TIGHT_PNG;
+     return tight_send_framebuffer_update(vs, x, y, w, h);
+ }
+ 
+ void vnc_tight_clear(VncState *vs)
+ {
+     int i;
+-    for (i=0; i<ARRAY_SIZE(vs->tight.stream); i++) {
+-        if (vs->tight.stream[i].opaque) {
+-            deflateEnd(&vs->tight.stream[i]);
++    for (i = 0; i < ARRAY_SIZE(vs->tight->stream); i++) {
++        if (vs->tight->stream[i].opaque) {
++            deflateEnd(&vs->tight->stream[i]);
+         }
+     }
+ 
+-    buffer_free(&vs->tight.tight);
+-    buffer_free(&vs->tight.zlib);
+-    buffer_free(&vs->tight.gradient);
++    buffer_free(&vs->tight->tight);
++    buffer_free(&vs->tight->zlib);
++    buffer_free(&vs->tight->gradient);
+ #ifdef CONFIG_VNC_JPEG
+-    buffer_free(&vs->tight.jpeg);
++    buffer_free(&vs->tight->jpeg);
+ #endif
+ #ifdef CONFIG_VNC_PNG
+-    buffer_free(&vs->tight.png);
++    buffer_free(&vs->tight->png);
+ #endif
+ }
+diff --git a/ui/vnc-enc-zlib.c b/ui/vnc-enc-zlib.c
+index 33e9df2..900ae5b 100644
+--- a/ui/vnc-enc-zlib.c
++++ b/ui/vnc-enc-zlib.c
+@@ -76,7 +76,8 @@ static int vnc_zlib_stop(VncState *vs)
+         zstream->zalloc = vnc_zlib_zalloc;
+         zstream->zfree = vnc_zlib_zfree;
+ 
+-        err = deflateInit2(zstream, vs->tight.compression, Z_DEFLATED, MAX_WBITS,
++        err = deflateInit2(zstream, vs->tight->compression, Z_DEFLATED,
++                           MAX_WBITS,
+                            MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
+ 
+         if (err != Z_OK) {
+@@ -84,16 +85,16 @@ static int vnc_zlib_stop(VncState *vs)
+             return -1;
+         }
+ 
+-        vs->zlib.level = vs->tight.compression;
++        vs->zlib.level = vs->tight->compression;
+         zstream->opaque = vs;
+     }
+ 
+-    if (vs->tight.compression != vs->zlib.level) {
+-        if (deflateParams(zstream, vs->tight.compression,
++    if (vs->tight->compression != vs->zlib.level) {
++        if (deflateParams(zstream, vs->tight->compression,
+                           Z_DEFAULT_STRATEGY) != Z_OK) {
+             return -1;
+         }
+-        vs->zlib.level = vs->tight.compression;
++        vs->zlib.level = vs->tight->compression;
+     }
+ 
+     // reserve memory in output buffer
+diff --git a/ui/vnc-enc-zrle.c b/ui/vnc-enc-zrle.c
+index 7493a84..17fd28a 100644
+--- a/ui/vnc-enc-zrle.c
++++ b/ui/vnc-enc-zrle.c
+@@ -37,18 +37,18 @@ static const int bits_per_packed_pixel[] = {
+ 
+ static void vnc_zrle_start(VncState *vs)
+ {
+-    buffer_reset(&vs->zrle.zrle);
++    buffer_reset(&vs->zrle->zrle);
+ 
+     /* make the output buffer be the zlib buffer, so we can compress it later */
+-    vs->zrle.tmp = vs->output;
+-    vs->output = vs->zrle.zrle;
++    vs->zrle->tmp = vs->output;
++    vs->output = vs->zrle->zrle;
+ }
+ 
+ static void vnc_zrle_stop(VncState *vs)
+ {
+     /* switch back to normal output/zlib buffers */
+-    vs->zrle.zrle = vs->output;
+-    vs->output = vs->zrle.tmp;
++    vs->zrle->zrle = vs->output;
++    vs->output = vs->zrle->tmp;
+ }
+ 
+ static void *zrle_convert_fb(VncState *vs, int x, int y, int w, int h,
+@@ -56,24 +56,24 @@ static void *zrle_convert_fb(VncState *vs, int x, int y, int w, int h,
+ {
+     Buffer tmp;
+ 
+-    buffer_reset(&vs->zrle.fb);
+-    buffer_reserve(&vs->zrle.fb, w * h * bpp + bpp);
++    buffer_reset(&vs->zrle->fb);
++    buffer_reserve(&vs->zrle->fb, w * h * bpp + bpp);
+ 
+     tmp = vs->output;
+-    vs->output = vs->zrle.fb;
++    vs->output = vs->zrle->fb;
+ 
+     vnc_raw_send_framebuffer_update(vs, x, y, w, h);
+ 
+-    vs->zrle.fb = vs->output;
++    vs->zrle->fb = vs->output;
+     vs->output = tmp;
+-    return vs->zrle.fb.buffer;
++    return vs->zrle->fb.buffer;
+ }
+ 
+ static int zrle_compress_data(VncState *vs, int level)
+ {
+-    z_streamp zstream = &vs->zrle.stream;
++    z_streamp zstream = &vs->zrle->stream;
+ 
+-    buffer_reset(&vs->zrle.zlib);
++    buffer_reset(&vs->zrle->zlib);
+ 
+     if (zstream->opaque != vs) {
+         int err;
+@@ -93,13 +93,13 @@ static int zrle_compress_data(VncState *vs, int level)
+     }
+ 
+     /* reserve memory in output buffer */
+-    buffer_reserve(&vs->zrle.zlib, vs->zrle.zrle.offset + 64);
++    buffer_reserve(&vs->zrle->zlib, vs->zrle->zrle.offset + 64);
+ 
+     /* set pointers */
+-    zstream->next_in = vs->zrle.zrle.buffer;
+-    zstream->avail_in = vs->zrle.zrle.offset;
+-    zstream->next_out = vs->zrle.zlib.buffer + vs->zrle.zlib.offset;
+-    zstream->avail_out = vs->zrle.zlib.capacity - vs->zrle.zlib.offset;
++    zstream->next_in = vs->zrle->zrle.buffer;
++    zstream->avail_in = vs->zrle->zrle.offset;
++    zstream->next_out = vs->zrle->zlib.buffer + vs->zrle->zlib.offset;
++    zstream->avail_out = vs->zrle->zlib.capacity - vs->zrle->zlib.offset;
+     zstream->data_type = Z_BINARY;
+ 
+     /* start encoding */
+@@ -108,8 +108,8 @@ static int zrle_compress_data(VncState *vs, int level)
+         return -1;
+     }
+ 
+-    vs->zrle.zlib.offset = vs->zrle.zlib.capacity - zstream->avail_out;
+-    return vs->zrle.zlib.offset;
++    vs->zrle->zlib.offset = vs->zrle->zlib.capacity - zstream->avail_out;
++    return vs->zrle->zlib.offset;
+ }
+ 
+ /* Try to work out whether to use RLE and/or a palette.  We do this by
+@@ -259,14 +259,14 @@ static int zrle_send_framebuffer_update(VncState *vs, int x, int y,
+     size_t bytes;
+     int zywrle_level;
+ 
+-    if (vs->zrle.type == VNC_ENCODING_ZYWRLE) {
+-        if (!vs->vd->lossy || vs->tight.quality == (uint8_t)-1
+-            || vs->tight.quality == 9) {
++    if (vs->zrle->type == VNC_ENCODING_ZYWRLE) {
++        if (!vs->vd->lossy || vs->tight->quality == (uint8_t)-1
++            || vs->tight->quality == 9) {
+             zywrle_level = 0;
+-            vs->zrle.type = VNC_ENCODING_ZRLE;
+-        } else if (vs->tight.quality < 3) {
++            vs->zrle->type = VNC_ENCODING_ZRLE;
++        } else if (vs->tight->quality < 3) {
+             zywrle_level = 3;
+-        } else if (vs->tight.quality < 6) {
++        } else if (vs->tight->quality < 6) {
+             zywrle_level = 2;
+         } else {
+             zywrle_level = 1;
+@@ -337,30 +337,30 @@ static int zrle_send_framebuffer_update(VncState *vs, int x, int y,
+ 
+     vnc_zrle_stop(vs);
+     bytes = zrle_compress_data(vs, Z_DEFAULT_COMPRESSION);
+-    vnc_framebuffer_update(vs, x, y, w, h, vs->zrle.type);
++    vnc_framebuffer_update(vs, x, y, w, h, vs->zrle->type);
+     vnc_write_u32(vs, bytes);
+-    vnc_write(vs, vs->zrle.zlib.buffer, vs->zrle.zlib.offset);
++    vnc_write(vs, vs->zrle->zlib.buffer, vs->zrle->zlib.offset);
+     return 1;
+ }
+ 
+ int vnc_zrle_send_framebuffer_update(VncState *vs, int x, int y, int w, int h)
+ {
+-    vs->zrle.type = VNC_ENCODING_ZRLE;
++    vs->zrle->type = VNC_ENCODING_ZRLE;
+     return zrle_send_framebuffer_update(vs, x, y, w, h);
+ }
+ 
+ int vnc_zywrle_send_framebuffer_update(VncState *vs, int x, int y, int w, int h)
+ {
+-    vs->zrle.type = VNC_ENCODING_ZYWRLE;
++    vs->zrle->type = VNC_ENCODING_ZYWRLE;
+     return zrle_send_framebuffer_update(vs, x, y, w, h);
+ }
+ 
+ void vnc_zrle_clear(VncState *vs)
+ {
+-    if (vs->zrle.stream.opaque) {
+-        deflateEnd(&vs->zrle.stream);
++    if (vs->zrle->stream.opaque) {
++        deflateEnd(&vs->zrle->stream);
+     }
+-    buffer_free(&vs->zrle.zrle);
+-    buffer_free(&vs->zrle.fb);
+-    buffer_free(&vs->zrle.zlib);
++    buffer_free(&vs->zrle->zrle);
++    buffer_free(&vs->zrle->fb);
++    buffer_free(&vs->zrle->zlib);
+ }
+diff --git a/ui/vnc-enc-zrle.inc.c b/ui/vnc-enc-zrle.inc.c
+index abf6b86..c107d8a 100644
+--- a/ui/vnc-enc-zrle.inc.c
++++ b/ui/vnc-enc-zrle.inc.c
+@@ -96,7 +96,7 @@ static void ZRLE_ENCODE(VncState *vs, int x, int y, int w, int h,
+ static void ZRLE_ENCODE_TILE(VncState *vs, ZRLE_PIXEL *data, int w, int h,
+                              int zywrle_level)
+ {
+-    VncPalette *palette = &vs->zrle.palette;
++    VncPalette *palette = &vs->zrle->palette;
+ 
+     int runs = 0;
+     int single_pixels = 0;
+diff --git a/ui/vnc.c b/ui/vnc.c
+index bc43c4c..87b8045 100644
+--- a/ui/vnc.c
++++ b/ui/vnc.c
+@@ -1307,6 +1307,8 @@ void vnc_disconnect_finish(VncState *vs)
+     object_unref(OBJECT(vs->sioc));
+     vs->sioc = NULL;
+     vs->magic = 0;
++    g_free(vs->zrle);
++    g_free(vs->tight);
+     g_free(vs);
+ }
+ 
+@@ -2058,8 +2060,8 @@ static void set_encodings(VncState *vs, int32_t *encodings, size_t n_encodings)
+ 
+     vs->features = 0;
+     vs->vnc_encoding = 0;
+-    vs->tight.compression = 9;
+-    vs->tight.quality = -1; /* Lossless by default */
++    vs->tight->compression = 9;
++    vs->tight->quality = -1; /* Lossless by default */
+     vs->absolute = -1;
+ 
+     /*
+@@ -2127,11 +2129,11 @@ static void set_encodings(VncState *vs, int32_t *encodings, size_t n_encodings)
+             vs->features |= VNC_FEATURE_LED_STATE_MASK;
+             break;
+         case VNC_ENCODING_COMPRESSLEVEL0 ... VNC_ENCODING_COMPRESSLEVEL0 + 9:
+-            vs->tight.compression = (enc & 0x0F);
++            vs->tight->compression = (enc & 0x0F);
+             break;
+         case VNC_ENCODING_QUALITYLEVEL0 ... VNC_ENCODING_QUALITYLEVEL0 + 9:
+             if (vs->vd->lossy) {
+-                vs->tight.quality = (enc & 0x0F);
++                vs->tight->quality = (enc & 0x0F);
+             }
+             break;
+         default:
+@@ -3034,6 +3036,8 @@ static void vnc_connect(VncDisplay *vd, QIOChannelSocket *sioc,
+     int i;
+ 
+     trace_vnc_client_connect(vs, sioc);
++    vs->zrle = g_new0(VncZrle, 1);
++    vs->tight = g_new0(VncTight, 1);
+     vs->magic = VNC_MAGIC;
+     vs->sioc = sioc;
+     object_ref(OBJECT(vs->sioc));
+@@ -3045,19 +3049,19 @@ static void vnc_connect(VncDisplay *vd, QIOChannelSocket *sioc,
+     buffer_init(&vs->output,         "vnc-output/%p", sioc);
+     buffer_init(&vs->jobs_buffer,    "vnc-jobs_buffer/%p", sioc);
+ 
+-    buffer_init(&vs->tight.tight,    "vnc-tight/%p", sioc);
+-    buffer_init(&vs->tight.zlib,     "vnc-tight-zlib/%p", sioc);
+-    buffer_init(&vs->tight.gradient, "vnc-tight-gradient/%p", sioc);
++    buffer_init(&vs->tight->tight,    "vnc-tight/%p", sioc);
++    buffer_init(&vs->tight->zlib,     "vnc-tight-zlib/%p", sioc);
++    buffer_init(&vs->tight->gradient, "vnc-tight-gradient/%p", sioc);
+ #ifdef CONFIG_VNC_JPEG
+-    buffer_init(&vs->tight.jpeg,     "vnc-tight-jpeg/%p", sioc);
++    buffer_init(&vs->tight->jpeg,     "vnc-tight-jpeg/%p", sioc);
+ #endif
+ #ifdef CONFIG_VNC_PNG
+-    buffer_init(&vs->tight.png,      "vnc-tight-png/%p", sioc);
++    buffer_init(&vs->tight->png,      "vnc-tight-png/%p", sioc);
+ #endif
+     buffer_init(&vs->zlib.zlib,      "vnc-zlib/%p", sioc);
+-    buffer_init(&vs->zrle.zrle,      "vnc-zrle/%p", sioc);
+-    buffer_init(&vs->zrle.fb,        "vnc-zrle-fb/%p", sioc);
+-    buffer_init(&vs->zrle.zlib,      "vnc-zrle-zlib/%p", sioc);
++    buffer_init(&vs->zrle->zrle,      "vnc-zrle/%p", sioc);
++    buffer_init(&vs->zrle->fb,        "vnc-zrle-fb/%p", sioc);
++    buffer_init(&vs->zrle->zlib,      "vnc-zrle-zlib/%p", sioc);
+ 
+     if (skipauth) {
+         vs->auth = VNC_AUTH_NONE;
+diff --git a/ui/vnc.h b/ui/vnc.h
+index 8643860..fea79c2 100644
+--- a/ui/vnc.h
++++ b/ui/vnc.h
+@@ -338,10 +338,10 @@ struct VncState
+     /* Encoding specific, if you add something here, don't forget to
+      *  update vnc_async_encoding_start()
+      */
+-    VncTight tight;
++    VncTight *tight;
+     VncZlib zlib;
+     VncHextile hextile;
+-    VncZrle zrle;
++    VncZrle *zrle;
+     VncZywrle zywrle;
+ 
+     Notifier mouse_mode_notifier;
+-- 
+1.8.3.1