b60fe990c6
The first/last indexes are typically shared with a user app. The app can change the 'last' index that the kernel uses to store the next result. This change sanity checks the index before using it for writing to a potentially arbitrary address. This fixes CVE-2019-14821. Cc: stable@vger.kernel.org Fixes: 5f94c1741bdc ("KVM: Add coalesced MMIO support (common part)") Signed-off-by: Matt Delco <delco@chromium.org> Signed-off-by: Jim Mattson <jmattson@google.com> Reported-by: syzbot+983c866c3dd6efa3662a@syzkaller.appspotmail.com [Use READ_ONCE. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.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.