C语言AVL树项目出现Segmentation fault，求Valgrind报错分析

我正在做一个C语言AVL树的课程项目，代码可正常编译，但运行时会终止并提示Segmentation fault (core dumped)。以下是Valgrind的报错信息：

==210456== Invalid read of size 8
==210456==    at 0x1095B5: rotate_left (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==    by 0x10968C: rotate_double_right (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==    by 0x109C6E: treat_shrink_left (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==    by 0x109DBC: remove_leftmost_son (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==    by 0x109E15: actual_remove (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==    by 0x10A098: remove_info (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==    by 0x109FB6: remove_info (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==    by 0x10A31E: main (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==  Address 0x18 is not stack'd, malloc'd or (recently) free'd
==210456== 
==210456== 
==210456== Process terminating with default action of signal 11 (SIGSEGV)
==210456==  Access not within mapped region at address 0x18
==210456==    at 0x1095B5: rotate_left (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==    by 0x10968C: rotate_double_right (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==    by 0x109C6E: treat_shrink_left (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==    by 0x109DBC: remove_leftmost_son (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==    by 0x109E15: actual_remove (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==    by 0x10A098: remove_info (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==    by 0x109FB6: remove_info (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==    by 0x10A31E: main (in /home/asteria/Documents/MC202/MC202_024/lab05/main)
==210456==  If you believe this happened as a result of a stack
==210456==  overflow in your program's main thread (unlikely but
==210456==  possible), you can try to increase the size of the
==210456==  main thread stack using the --main-stacksize= flag.
==210456==  The main thread stack size used in this run was 8388608.

我无法理解这些报错信息，希望有人能帮忙分析解决。谢谢！

内容的提问来源于stack exchange，提问作者Asteria101