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af40322e90
All kind of administrative requests should not been retried. Some card firmware detects this and assumes a replay attack. This patch checks on failure if the low level functions indicate a retry (EAGAIN) and checks for the ADMIN flag set on the request message. If this both are true, the response code for this message is changed to EIO to make sure the zcrypt API layer does not attempt to retry the request. As of now the ADMIN flag is set for a request message when - for EP11 the field 'flags' of the EP11 CPRB struct has the leftmost bit set. - for CCA when the CPRB minor version is 'T3', 'T5', 'T6' or 'T7'. Please note that the do-not-retry only applies to a request which has been sent to the card (= has been successfully enqueued) but the reply indicates some kind of failure and by default it would be replied. It is totally fine to retry a request if a previous attempt to enqueue the msg into the firmware queue had some kind of failure and thus the card has never seen this request. Reported-by: Frank Uhlig <Frank.Uhlig1@ibm.com> Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Cc: stable@vger.kernel.org Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.