I get this kinda error frequently, how can I practice so that get less this kind of errors..
==30==ERROR: AddressSanitizer: heap-use-after-free on address 0x603000000108 at pc 0x000000480f1a bp 0x7ffdfadb0600 sp 0x7ffdfadb05f8
READ of size 8 at 0x603000000108 thread T0
#8 0x7fdf7b8c62e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
0x603000000108 is located 8 bytes inside of 24-byte region [0x603000000100,0x603000000118)
freed by thread T0 here:
#0 0x7fdf7d2ed0d8 in operator delete(void*, unsigned long) (/usr/local/lib64/libasan.so.5+0xeb0d8)
#9 0x7fdf7b8c62e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
previously allocated by thread T0 here:
#0 0x7fdf7d2ebce0 in operator new(unsigned long) (/usr/local/lib64/libasan.so.5+0xe9ce0)
#4 0x7fdf7b8c62e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
Shadow bytes around the buggy address:
0x0c067fff7fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c067fff7fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c067fff7ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x0c067fff8000: fa fa 00 00 00 fa fa fa 00 00 00 fa fa fa 00 00
0x0c067fff8010: 00 fa fa fa 00 00 00 fa fa fa 00 00 00 fa fa fa
=>0x0c067fff8020: fd[fd]fd fa fa fa fd fd fd fa fa fa fd fd fd fd
0x0c067fff8030: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c067fff8040: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c067fff8050: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c067fff8060: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c067fff8070: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb