4e4a08868f
An often overlooked aspect of the skcipher walker API is that an
error is not just indicated by a non-zero return value, but by the
fact that walk->nbytes is zero.
Thus it is an error to call skcipher_walk_done after getting back
walk->nbytes == 0 from the previous interaction with the walker.
This is because when walk->nbytes is zero the walker is left in
an undefined state and any further calls to it may try to free
uninitialised stack memory.
The sm4 arm64 ccm code gets this wrong and ends up calling
skcipher_walk_done even when walk->nbytes is zero.
This patch rewrites the loop in a form that resembles other callers.
Reported-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Fixes: ae1b83c7d572 ("crypto: arm64/sm4 - add CE implementation for GCM mode")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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.