GitLab

Avoid overreading if record is too short.

TOCTOU between data size check and read: attacker could replace cache
file with larger one and cause buffer overflow.

In case of a corrupt file it could happen that len get 0 in _record
and this results in an endless loop.
Created an exit condition for this case and fixed related
procedures too (they need to cope with the error-return-value
from _record).
Reason for change: https://github.com/OpenELEC/OpenELEC.tv/pull/4378

In case of a AACS_ERROR_CORRUPTED_DISC error always write a BD_DEBUG
message at DBG_CRIT loglevel.

'discid' sent to BD_DEBUG has not been converted to string before
and resulted in a broken output - corrected.

Fix handling of errors when reading MKB.