mirror of
https://github.com/torvalds/linux.git
synced 2026-10-07 05:31:08 -04:00
Joerg Roedel
ed7b895f3e
The early #VC handler which doesn't have a GHCB can only handle CPUID exit codes. It is needed by the early boot code to handle #VC exceptions raised in verify_cpu() and to get the position of the C-bit. But the CPUID information comes from the hypervisor which is untrusted and might return results which trick the guest into the no-SEV boot path with no C-bit set in the page-tables. All data written to memory would then be unencrypted and could leak sensitive data to the hypervisor. Add sanity checks to the early #VC handler to make sure the hypervisor can not pretend that SEV is disabled. [ bp: Massage a bit. ] Signed-off-by: Joerg Roedel <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Tom Lendacky <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
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.