Catching a double free or corruption error with memcheck (a Valgrind tool)

I was randomly getting errors (1 run in 50 would reproduce) like:

$ ./myprogram
*** glibc detected *** double free or corruption (out): 0x093014a4 ***

Linux has a randomization of virtual address space which is supposed to help thwart buffer overflow attacks etc.

This can cause errors to randomly not show, so in the spirit of trying to consistently reproduce the problem I disabled this using:

$ setarch x86_64 -R ./myprogram

This didn’t seem to help.

$ valgrind --tool=memcheck ./myprogram

The output of this produced a:

Invalid free which showed where the error was.