lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <cover.1729628198.git.lorenzo.stoakes@oracle.com>
Date: Tue, 22 Oct 2024 21:40:51 +0100
From: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: "Liam R . Howlett" <Liam.Howlett@...cle.com>,
        Vlastimil Babka <vbabka@...e.cz>, Jann Horn <jannh@...gle.com>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Peter Xu <peterx@...hat.com>
Subject: [PATCH hotfix 6.12 0/8] fix error handling in mmap_region() and refactor

The mmap_region() function is somewhat terrifying, with spaghetti-like
control flow and numerous means by which issues can arise and incomplete
state, memory leaks and other unpleasantness can occur.

A large amount of the complexity arises from trying to handle errors late
in the process of mapping a VMA, which forms the basis of recently observed
issues with resource leaks and observable inconsistent state.

This series goes to great lengths to simplify how mmap_region() works and
to avoid unwinding errors late on in the process of setting up the VMA for
the new mapping, and equally avoids such operations occurring while the VMA
is in an inconsistent state.

The first four patches are intended for backporting to correct the
possibility of people encountering corrupted state while invoking mmap()
which is otherwise at risk of happening.

After this we go further, refactoring the code, placing it in mm/vma.c in
order to make it eventually userland testable, and significantly
simplifying the logic to avoid this issue arising in future.

Lorenzo Stoakes (8):
  mm: avoid unsafe VMA hook invocation when error arises on mmap hook
  mm: unconditionally close VMAs on error
  mm: refactor map_deny_write_exec()
  mm: resolve faulty mmap_region() error path behaviour
  tools: testing: add additional vma_internal.h stubs
  mm: insolate mmap internal logic to mm/vma.c
  mm: refactor __mmap_region()
  mm: do not attempt second merge for file-backed VMAs

 include/linux/mman.h             |  21 +-
 mm/internal.h                    |  44 ++++
 mm/mmap.c                        | 262 ++------------------
 mm/mprotect.c                    |   2 +-
 mm/nommu.c                       |   7 +-
 mm/vma.c                         | 403 ++++++++++++++++++++++++++++++-
 mm/vma.h                         | 101 +-------
 mm/vma_internal.h                |   5 +
 tools/testing/vma/vma_internal.h | 106 +++++++-
 9 files changed, 591 insertions(+), 360 deletions(-)

--
2.47.0

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ