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Kees Cook 439a846824 binfmt_elf: Avoid total_mapping_size for ET_EXEC
Partially revert commit 5f501d5556 ("binfmt_elf: reintroduce using
MAP_FIXED_NOREPLACE"), which applied the ET_DYN "total_mapping_size"
logic also to ET_EXEC.

At least ia64 has ET_EXEC PT_LOAD segments that are not virtual-address
contiguous (but _are_ file-offset contiguous). This would result in a
giant mapping attempting to cover the entire span, including the virtual
address range hole, and well beyond the size of the ELF file itself,
causing the kernel to refuse to load it. For example:

$ readelf -lW /usr/bin/gcc
...
Program Headers:
  Type Offset   VirtAddr           PhysAddr           FileSiz  MemSiz   ...
...
  LOAD 0x000000 0x4000000000000000 0x4000000000000000 0x00b5a0 0x00b5a0 ...
  LOAD 0x00b5a0 0x600000000000b5a0 0x600000000000b5a0 0x0005ac 0x000710 ...
...
       ^^^^^^^^ ^^^^^^^^^^^^^^^^^^                    ^^^^^^^^ ^^^^^^^^

File offset range     : 0x000000-0x00bb4c
			0x00bb4c bytes

Virtual address range : 0x4000000000000000-0x600000000000bcb0
			0x200000000000bcb0 bytes

Remove the total_mapping_size logic for ET_EXEC, which reduces the
ET_EXEC MAP_FIXED_NOREPLACE coverage to only the first PT_LOAD (better
than nothing), and retains it for ET_DYN.

Ironically, this is the reverse of the problem that originally caused
problems with MAP_FIXED_NOREPLACE: overlapping PT_LOAD segments. Future
work could restore full coverage if load_elf_binary() were to perform
mappings in a separate phase from the loading (where it could resolve
both overlaps and holes).

Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mm@kvack.org
Reported-by: matoro <matoro_bugzilla_kernel@matoro.tk>
Fixes: 5f501d5556 ("binfmt_elf: reintroduce using MAP_FIXED_NOREPLACE")
Link: https://lore.kernel.org/r/a3edd529-c42d-3b09-135c-7e98a15b150f@leemhuis.info
Tested-by: matoro <matoro_mailinglist_kernel@matoro.tk>
Link: https://lore.kernel.org/lkml/ce8af9c13bcea9230c7689f3c1e0e2cd@matoro.tk
Tested-By: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/lkml/49182d0d-708b-4029-da5f-bc18603440a6@physik.fu-berlin.de
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2022-03-01 10:29:20 -08:00
arch perf/urgent contains 3 fixups: 2022-02-06 10:11:14 -08:00
block block: bio-integrity: Advance seed correctly for larger interval sizes 2022-02-03 21:09:24 -07:00
certs certs: Fix build error when CONFIG_MODULE_SIG_KEY is empty 2022-01-23 00:08:44 +09:00
crypto lib/crypto: blake2s: avoid indirect calls to compression function for Clang CFI 2022-02-04 19:22:32 +01:00
Documentation xen: branch for v5.17-rc3 2022-02-05 10:40:17 -08:00
drivers - Remove a bogus warning introduced by the recent PCI MSI irq affinity 2022-02-06 10:00:40 -08:00
fs binfmt_elf: Avoid total_mapping_size for ET_EXEC 2022-03-01 10:29:20 -08:00
include Various bug fixes for ext4 fast commit and inline data handling. Also 2022-02-06 10:34:45 -08:00
init lib/stackdepot: allow optional init and stack_table allocation by kvmalloc() 2022-01-22 08:33:37 +02:00
ipc ipc/sem: do not sleep with a spin lock held 2022-02-04 09:25:05 -08:00
kernel perf/urgent contains 3 fixups: 2022-02-06 10:11:14 -08:00
lib lib/crypto: blake2s: avoid indirect calls to compression function for Clang CFI 2022-02-04 19:22:32 +01:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm/kmemleak: avoid scanning potential huge holes 2022-02-04 09:25:05 -08:00
net A patch to make it possible to disable zero copy path in the messenger 2022-02-04 09:54:02 -08:00
samples Merge branch 'akpm' (patches from Andrew) 2022-01-20 10:41:01 +02:00
scripts ftrace: Have architectures opt-in for mcount build time sorting 2022-01-27 19:15:44 -05:00
security selinux/stable-5.17 PR 20220203 2022-02-03 16:44:12 -08:00
sound ASoC: Fixes for v5.17 2022-02-01 16:52:54 +01:00
tools perf tools fixes for v5.17: 1st batch 2022-02-06 10:18:23 -08:00
usr kbuild: remove include/linux/cyclades.h from header file check 2022-01-27 08:51:08 +01:00
virt Two larger x86 series: 2022-01-28 19:00:26 +02:00
.clang-format genirq/msi: Make interrupt allocation less convoluted 2021-12-16 22:22:20 +01:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: update Christian Brauner's email address 2022-02-01 11:21:31 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Removing Ohad from remoteproc/rpmsg maintenance 2021-12-08 10:09:40 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS ata fixes for 5.17-rc3 2022-02-04 11:52:37 -08:00
Makefile Linux 5.17-rc3 2022-02-06 12:20:50 -08:00
README

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.