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qemu-e2k/ui/vnc-enc-zrle.c
Li Qiang 6bf21f3d83 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>
2019-09-17 13:45:10 +02:00

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/*
* QEMU VNC display driver: Zlib Run-length Encoding (ZRLE)
*
* From libvncserver/libvncserver/zrle.c
* Copyright (C) 2002 RealVNC Ltd. All Rights Reserved.
* Copyright (C) 2003 Sun Microsystems, Inc.
*
* Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "vnc.h"
#include "vnc-enc-zrle.h"
static const int bits_per_packed_pixel[] = {
0, 1, 2, 2, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4
};
static void vnc_zrle_start(VncState *vs)
{
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;
}
static void vnc_zrle_stop(VncState *vs)
{
/* switch back to normal output/zlib buffers */
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,
int bpp)
{
Buffer tmp;
buffer_reset(&vs->zrle->fb);
buffer_reserve(&vs->zrle->fb, w * h * bpp + bpp);
tmp = vs->output;
vs->output = vs->zrle->fb;
vnc_raw_send_framebuffer_update(vs, x, y, w, h);
vs->zrle->fb = vs->output;
vs->output = tmp;
return vs->zrle->fb.buffer;
}
static int zrle_compress_data(VncState *vs, int level)
{
z_streamp zstream = &vs->zrle->stream;
buffer_reset(&vs->zrle->zlib);
if (zstream->opaque != vs) {
int err;
zstream->zalloc = vnc_zlib_zalloc;
zstream->zfree = vnc_zlib_zfree;
err = deflateInit2(zstream, level, Z_DEFLATED, MAX_WBITS,
MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
if (err != Z_OK) {
fprintf(stderr, "VNC: error initializing zlib\n");
return -1;
}
zstream->opaque = vs;
}
/* reserve memory in output buffer */
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->data_type = Z_BINARY;
/* start encoding */
if (deflate(zstream, Z_SYNC_FLUSH) != Z_OK) {
fprintf(stderr, "VNC: error during zrle compression\n");
return -1;
}
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
* estimating the number of bytes which will be generated and picking the
* method which results in the fewest bytes. Of course this may not result
* in the fewest bytes after compression... */
static void zrle_choose_palette_rle(VncState *vs, int w, int h,
VncPalette *palette, int bpp_out,
int runs, int single_pixels,
int zywrle_level,
bool *use_rle, bool *use_palette)
{
size_t estimated_bytes;
size_t plain_rle_bytes;
*use_palette = *use_rle = false;
estimated_bytes = w * h * (bpp_out / 8); /* start assuming raw */
if (bpp_out != 8) {
if (zywrle_level > 0 && !(zywrle_level & 0x80))
estimated_bytes >>= zywrle_level;
}
plain_rle_bytes = ((bpp_out / 8) + 1) * (runs + single_pixels);
if (plain_rle_bytes < estimated_bytes) {
*use_rle = true;
estimated_bytes = plain_rle_bytes;
}
if (palette_size(palette) < 128) {
int palette_rle_bytes;
palette_rle_bytes = (bpp_out / 8) * palette_size(palette);
palette_rle_bytes += 2 * runs + single_pixels;
if (palette_rle_bytes < estimated_bytes) {
*use_rle = true;
*use_palette = true;
estimated_bytes = palette_rle_bytes;
}
if (palette_size(palette) < 17) {
int packed_bytes;
packed_bytes = (bpp_out / 8) * palette_size(palette);
packed_bytes += w * h *
bits_per_packed_pixel[palette_size(palette)-1] / 8;
if (packed_bytes < estimated_bytes) {
*use_rle = false;
*use_palette = true;
}
}
}
}
static void zrle_write_u32(VncState *vs, uint32_t value)
{
vnc_write(vs, (uint8_t *)&value, 4);
}
static void zrle_write_u24a(VncState *vs, uint32_t value)
{
vnc_write(vs, (uint8_t *)&value, 3);
}
static void zrle_write_u24b(VncState *vs, uint32_t value)
{
vnc_write(vs, ((uint8_t *)&value) + 1, 3);
}
static void zrle_write_u16(VncState *vs, uint16_t value)
{
vnc_write(vs, (uint8_t *)&value, 2);
}
static void zrle_write_u8(VncState *vs, uint8_t value)
{
vnc_write_u8(vs, value);
}
#define ENDIAN_LITTLE 0
#define ENDIAN_BIG 1
#define ENDIAN_NO 2
#define ZRLE_BPP 8
#define ZYWRLE_ENDIAN ENDIAN_NO
#include "vnc-enc-zrle.inc.c"
#undef ZRLE_BPP
#define ZRLE_BPP 15
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_LITTLE
#include "vnc-enc-zrle.inc.c"
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_BIG
#include "vnc-enc-zrle.inc.c"
#undef ZRLE_BPP
#define ZRLE_BPP 16
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_LITTLE
#include "vnc-enc-zrle.inc.c"
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_BIG
#include "vnc-enc-zrle.inc.c"
#undef ZRLE_BPP
#define ZRLE_BPP 32
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_LITTLE
#include "vnc-enc-zrle.inc.c"
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_BIG
#include "vnc-enc-zrle.inc.c"
#define ZRLE_COMPACT_PIXEL 24a
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_LITTLE
#include "vnc-enc-zrle.inc.c"
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_BIG
#include "vnc-enc-zrle.inc.c"
#undef ZRLE_COMPACT_PIXEL
#define ZRLE_COMPACT_PIXEL 24b
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_LITTLE
#include "vnc-enc-zrle.inc.c"
#undef ZYWRLE_ENDIAN
#define ZYWRLE_ENDIAN ENDIAN_BIG
#include "vnc-enc-zrle.inc.c"
#undef ZRLE_COMPACT_PIXEL
#undef ZRLE_BPP
static int zrle_send_framebuffer_update(VncState *vs, int x, int y,
int w, int h)
{
bool be = vs->client_be;
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) {
zywrle_level = 0;
vs->zrle->type = VNC_ENCODING_ZRLE;
} else if (vs->tight->quality < 3) {
zywrle_level = 3;
} else if (vs->tight->quality < 6) {
zywrle_level = 2;
} else {
zywrle_level = 1;
}
} else {
zywrle_level = 0;
}
vnc_zrle_start(vs);
switch (vs->client_pf.bytes_per_pixel) {
case 1:
zrle_encode_8ne(vs, x, y, w, h, zywrle_level);
break;
case 2:
if (vs->client_pf.gmax > 0x1F) {
if (be) {
zrle_encode_16be(vs, x, y, w, h, zywrle_level);
} else {
zrle_encode_16le(vs, x, y, w, h, zywrle_level);
}
} else {
if (be) {
zrle_encode_15be(vs, x, y, w, h, zywrle_level);
} else {
zrle_encode_15le(vs, x, y, w, h, zywrle_level);
}
}
break;
case 4:
{
bool fits_in_ls3bytes;
bool fits_in_ms3bytes;
fits_in_ls3bytes =
((vs->client_pf.rmax << vs->client_pf.rshift) < (1 << 24) &&
(vs->client_pf.gmax << vs->client_pf.gshift) < (1 << 24) &&
(vs->client_pf.bmax << vs->client_pf.bshift) < (1 << 24));
fits_in_ms3bytes = (vs->client_pf.rshift > 7 &&
vs->client_pf.gshift > 7 &&
vs->client_pf.bshift > 7);
if ((fits_in_ls3bytes && !be) || (fits_in_ms3bytes && be)) {
if (be) {
zrle_encode_24abe(vs, x, y, w, h, zywrle_level);
} else {
zrle_encode_24ale(vs, x, y, w, h, zywrle_level);
}
} else if ((fits_in_ls3bytes && be) || (fits_in_ms3bytes && !be)) {
if (be) {
zrle_encode_24bbe(vs, x, y, w, h, zywrle_level);
} else {
zrle_encode_24ble(vs, x, y, w, h, zywrle_level);
}
} else {
if (be) {
zrle_encode_32be(vs, x, y, w, h, zywrle_level);
} else {
zrle_encode_32le(vs, x, y, w, h, zywrle_level);
}
}
}
break;
}
vnc_zrle_stop(vs);
bytes = zrle_compress_data(vs, Z_DEFAULT_COMPRESSION);
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);
return 1;
}
int vnc_zrle_send_framebuffer_update(VncState *vs, int x, int y, int w, int h)
{
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;
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);
}
buffer_free(&vs->zrle->zrle);
buffer_free(&vs->zrle->fb);
buffer_free(&vs->zrle->zlib);
}
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