Research: Bugs found in Kernel Linux (http://vbdb.itu.dk) and GNU C Compiler (GCC)
Tools: Git, Bugzilla and Tig
Bugs description (borders): Yellow (first commit); green (bugfix commit); blue (original code); red (bug).

Kernel Linux

buffer overflow dead code double acquiring lock assertion violation incompatible types
IndexOutOfBounds fail to release memory before removing last reference to it cannot allocate memory because there is not enough available null pointer dereference
numeric truncation read out of the intended bounds SysFS API violation undeclared identifier undefined symbol reference use of variable before initialization unused variable attempt to use a resource after having freed it warning: dereferencing `void *' pointer assertion violation attempt to write on read-only resource wrong number of arguments in function application

GCC