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vnc: fix memory leak when vnc disconnect

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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>
This commit is contained in:
Li Qiang
2019-09-17 13:45:10 +02:00
committed by Gerd Hoffmann
parent 6105683da3
commit 6bf21f3d83
6 changed files with 170 additions and 162 deletions
Download Patch File Download Diff File Expand all files Collapse all files
ui/vnc-enc-tight.c
+111 -108
View File
File diff suppressed because it is too large Load Diff
ui/vnc-enc-zlib.c
+6 -5
View File
@@ -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
ui/vnc-enc-zrle.c
+34 -34
View File
@@ -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);
}
ui/vnc-enc-zrle.inc.c
+1 -1
View File
@@ -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;
ui/vnc.c
+16 -12
View File
@@ -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;
ui/vnc.h
+2 -2
View File
@@ -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;