Understanding ASAN output - linux

Question

I have a problem figuring out why ASAN gives this output, why I can't see where and in what line the bug is in my code, is this bug even in my code as it says or is it in some libraries that is used by the program?
This is how I build my project :
CC=clang CXX=clang++ meson -Db_sanitize=address -Db_lundef=false
build-clang
and then I configure the env values and run the executable like this :
ASAN_OPTIONS=symbolize=1
ASAN_SYMBOLIZER_PATH=/usr/bin/llvm-symbolizer ./executable
And yes that is a valid path for llvm-sybolizer
So is there a way for me to know what does executable+0x431340 mean and where it points to in my code?
=================================================================
==13110==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 16384 byte(s) in 1 object(s) allocated from:
#0 0x4e1340 in __interceptor_malloc (/home/maysara/Desktop/testscreen/build-clang/src/excutable+0x4e1340)
#1 0x7ff16a2ccab8 in g_malloc (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x51ab8)
Direct leak of 4352 byte(s) in 17 object(s) allocated from:
#0 0x4e1340 in __interceptor_malloc (/home/maysara/Desktop/testscreen/build-clang/src/excutable+0x4e1340)
#1 0x7ff165e518ed (/usr/lib/x86_64-linux-gnu/libfontconfig.so.1+0x1d8ed)
Direct leak of 3840 byte(s) in 6 object(s) allocated from:
#0 0x4e17c0 in realloc (/home/maysara/Desktop/testscreen/build-clang/src/excutable+0x4e17c0)
#1 0x7ff165e51998 (/usr/lib/x86_64-linux-gnu/libfontconfig.so.1+0x1d998)
Direct leak of 24 byte(s) in 1 object(s) allocated from:
#0 0x4e1340 in __interceptor_malloc (/home/maysara/Desktop/testscreen/build-clang/src/excutable+0x4e1340)
#1 0x7ff16a2ccab8 in g_malloc (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x51ab8)
#2 0x7ff168b5910c in g_closure_invoke (/usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0+0x1010c)
Indirect leak of 10016 byte(s) in 313 object(s) allocated from:
#0 0x4e1340 in __interceptor_malloc (/home/maysara/Desktop/testscreen/build-clang/src/excutable+0x4e1340)
#1 0x7ff165e3ffef (/usr/lib/x86_64-linux-gnu/libfontconfig.so.1+0xbfef)
Indirect leak of 4887 byte(s) in 405 object(s) allocated from:
#0 0x43db60 in strdup (/home/maysara/Desktop/testscreen/build-clang/src/excutable+0x43db60)
#1 0x7ff165e512f4 in FcValueSave (/usr/lib/x86_64-linux-gnu/libfontconfig.so.1+0x1d2f4)
Indirect leak of 4320 byte(s) in 135 object(s) allocated from:
#0 0x4e1568 in calloc (/home/maysara/Desktop/testscreen/build-clang/src/excutable+0x4e1568)
#1 0x7ff165e51fd8 (/usr/lib/x86_64-linux-gnu/libfontconfig.so.1+0x1dfd8)
Indirect leak of 2400 byte(s) in 75 object(s) allocated from:
#0 0x4e1568 in calloc (/home/maysara/Desktop/testscreen/build-clang/src/excutable+0x4e1568)
#1 0x7ff165e515c4 (/usr/lib/x86_64-linux-gnu/libfontconfig.so.1+0x1d5c4)
Indirect leak of 576 byte(s) in 18 object(s) allocated from:
#0 0x4e1568 in calloc (/home/maysara/Desktop/testscreen/build-clang/src/excutable+0x4e1568)
#1 0x7ff165e51440 (/usr/lib/x86_64-linux-gnu/libfontconfig.so.1+0x1d440)
Indirect leak of 144 byte(s) in 3 object(s) allocated from:
#0 0x4e1340 in __interceptor_malloc (/home/maysara/Desktop/testscreen/build-clang/src/excutable+0x4e1340)
#1 0x7ff165e4bacd in FcLangSetCreate (/usr/lib/x86_64-linux-gnu/libfontconfig.so.1+0x17acd)
SUMMARY: AddressSanitizer: 46943 byte(s) leaked in 974 allocation(s).

Answer 1

In order to resolve the code addresses to source code locations, you need to compile the code with debug symbols enabled, e.g. with -g on the compiler command line or the commonly with build systems the environment variables CFLAGS and CXXFLAGS set accordingly:
CFLAGS="-g"
CXXFLAGS="-g"
That needs to be done for the code actually referenced, meaning here for example not only the code of executable, but also the linked libraries like glib, fontconfig, etc. if you want all addresses resolved.
Since these libraries are probably installed through a system package manager, you would need to look in your distribution's documentation how to install debug symbols. For Ubuntu, for example, there are usually variants of packages with an -dbg suffix.
In any case your stack traces do not look very helpful anyway, so it is not clear that finding the source code locations will be any help to you. You might want to recompile your executable with -fno-omit-frame-pointer and/or set the environment variable ASAN_OPTIONS=fast_unwind_on_malloc=0 when running the executable to try and improve them. See also the ASAN faq.