[Qemu-devel] [PATCH repost 0/4] add mitigation against buffer overflows

[Michael S. Tsirkin]

Multiple places in QEMU map guest memory, then access it
directly. Unfortunately since we are using C, there's always
a chance that we'll miss a bounds check when we do this.
This has a potential to corrupt QEMU memory.

As a mitigation strategy against such exploits,
allocate a page in HVA space on top of each RAM chunk
with PROT_NONE protection.

Buffer overflows will now cause QEMU to crash.

This is a repost, combining separate patches into a single
series. No changes to patches themselves.

Michael S. Tsirkin (4):
  oslib: rework anonimous RAM allocation
  oslib: allocate PROT_NONE pages on top of RAM
  exec: allocate PROT_NONE pages on top of RAM
  exec: factor out duplicate mmap code

 include/qemu/mmap-alloc.h | 10 +++++++++
 exec.c                    | 19 ++++++++++++-----
 util/mmap-alloc.c         | 52 +++++++++++++++++++++++++++++++++++++++++++++++
 util/oslib-posix.c        | 20 ++++--------------
 util/Makefile.objs        |  2 +-
 5 files changed, 81 insertions(+), 22 deletions(-)
 create mode 100644 include/qemu/mmap-alloc.h
 create mode 100644 util/mmap-alloc.c

-- 
MST