Concurrency issues with FILE ccache

[Greg Hudson]

On 4/6/21 11:48 AM, Osipov, Michael (LDA IT PLM) wrote:
> gssapi.raw.misc.GSSError: Major (851968): Unspecified GSS failure.  Minor code may provide more information, Minor (100001): Failed to store credentials: Internal credentials cache error (filename: /tmp/krb5cc_1000)

This is not expected, and bears investigation.  It suggests an EINVAL,
EEXIST, EFAULT, EBADF, or EWOULDBLOCK error from one of the I/O
operations performed by fcc_store(), none of which are expected.  If
you're building libkrb5, you could try modifying interpret_error() to
pass those error codes through in order to find out which one is happening.

Getting multiple cache entries for a service is normal when multiple
threads or processes initiate contexts to the same (new) service within
a short window.