fangying <fangyi...@huawei.com> 于2019年8月31日周六 上午8:45写道：
> Hi Gerd, > > Memory leak is observed in zrle_compress_data when we are doing some > AddressSanitizer tests. The leak stack is as bellow: > > ================================================================= > ==47887==ERROR: LeakSanitizer: detected memory leaks > > 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 leak stack can be easily reproduced in the case that a client > repeatedly > does vnc connect/disconnect . > > To get the leak stack, we can compile qemu with > --extra-ldflags=-Wl,--build-id -Wl,-z,relro -Wl,-z,now -lasan' > '--extra-cflags=-O0 -g -fno-omit-frame-pointer -fno-stack-protector > -fsanitize=address -fsanitize=leak' using gcc that supports asan. > > It is obvious that there may be memory leak in the zlib/zrle compress > stuff. > IIUC, *deflateInit2* is called with the local VncState vs->zrle.stream > when a > client is connected the vnc server. And then *deflate* is called to do the > encoding. Finally *deflateEnd* is called in vnc_zrle_clear when a > connection is > closed. > > I had not think it out why this memory leak could happen here. > It is noticed that deflateInit2 is called with the local vs, > however deflateEnd is called with the origin vs. > The local vs is copied to the origin vs in vnc_async_encoding_start and > vnc_async_encoding_end on the contrary. > > Have you got any idea on this issue ? > > Hello Ying, I have posted a patch for this issue: --> https://lists.gnu.org/archive/html/qemu-devel/2019-08/msg06675.html Please check whether the patch can address this issue. Thanks, Li Qiang > Thanks. > Ying Fang > > >
