Sean Christopherson df82a24b29 KVM: nVMX: Ensure vmcs01 is the loaded VMCS when freeing nested state
Add a WARN in free_nested() to ensure vmcs01 is loaded prior to freeing
vmcs02 and friends, and explicitly switch to vmcs01 if it's not.  KVM is
supposed to keep is_guest_mode() and loaded_vmcs==vmcs02 synchronized,
but bugs happen and freeing vmcs02 while it's in use will escalate a KVM
error to a use-after-free and potentially crash the kernel.

Do the WARN and switch even in the !vmxon case to help detect latent
bugs.  free_nested() is not a hot path, and the check is cheap.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200923184452.980-6-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28 07:57:46 -04:00
2020-09-06 17:11:40 -07:00

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.
Description
No description provided
Readme 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%