#11 String literal overwrite bug (5.05)

[Ian Abbott]

Serial 5.05

There is a string corruption bug that occurs when the
probe for PCI cards fails.

In function probe_serial_pci(), if the call to
pci_module_init() fails, the function ensures that
pci_unregister_driver() will not be called on module
exit (rs_fini()). It currently does this by overwriting
the first character of the string pointed to by
serial_pci_driver.name with a null character.
Unfortunately, this happens to be overwriting an
unnamed array of char initialized by the string literal
"serial" and this unnamed array of char is pointed to
by other parts of the driver due to optimization by the
compiler (the C standard refers to this as undefined
behavior).

I have submitted a patch for this bug in the Patches
tracker for this project - Patch #442034.