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Benjamin Herrenschmidt 4152433c39 arm64: efi: kaslr: Fix occasional random alloc (and boot) failure
The EFI stub random allocator used for kaslr on arm64 has a subtle
bug. In function get_entry_num_slots() which counts the number of
possible allocation "slots" for the image in a given chunk of free
EFI memory, "last_slot" can become negative if the chunk is smaller
than the requested allocation size.

The test "if (first_slot > last_slot)" doesn't catch it because
both first_slot and last_slot are unsigned.

I chose not to make them signed to avoid problems if this is ever
used on architectures where there are meaningful addresses with the
top bit set. Instead, fix it with an additional test against the
allocation size.

This can cause a boot failure in addition to a loss of randomisation
due to another bug in the arm64 stub fixed separately.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Fixes: 2ddbfc81ea ("efi: stub: add implementation of efi_random_alloc()")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2021-07-20 16:49:48 +02:00
Documentation RTC for 5.14 2021-07-10 16:19:10 -07:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
arch Two fixes: 2021-07-11 11:17:57 -07:00
block block-5.14-2021-07-08 2021-07-09 12:05:33 -07:00
certs Kbuild updates for v5.13 (2nd) 2021-05-08 10:00:11 -07:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2021-07-09 11:00:44 -07:00
drivers arm64: efi: kaslr: Fix occasional random alloc (and boot) failure 2021-07-20 16:49:48 +02:00
fs 13 cifs/smb3 fixes. Most are to address minor issues pointed out by Coverity. Also includes a packet signing enhancement and mount improvement 2021-07-10 12:04:58 -07:00
include Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
init Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
ipc Merge branch 'akpm' (patches from Andrew) 2021-07-02 12:08:10 -07:00
kernel Two fixes: 2021-07-11 11:17:57 -07:00
lib mm/page_alloc: Revert pahole zero-sized workaround 2021-07-10 16:09:39 -07:00
mm mm/rmap: try_to_migrate() skip zone_device !device_private 2021-07-11 15:05:15 -07:00
net We have new filesystem client metrics for reporting I/O sizes from 2021-07-09 09:52:13 -07:00
samples VFIO update for v5.14-rc1 2021-07-03 11:49:33 -07:00
scripts Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
security asm-generic/unaligned: Unify asm/unaligned.h around struct helper 2021-07-02 12:43:40 -07:00
sound sound fixes for 5.14-rc1 2021-07-09 11:40:26 -07:00
tools perf tools changes for v5.14: 2nd batch 2021-07-11 10:54:24 -07:00
usr .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
virt Merge branch 'akpm' (patches from Andrew) 2021-06-29 17:29:11 -07:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.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 m68k updates for v5.14 2021-06-28 14:01:03 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: move Murali Karicheri to credits 2021-04-29 15:47:30 -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 SCSI misc on 20210711 2021-07-11 10:59:53 -07:00
Makefile Linux 5.14-rc1 2021-07-11 15:07:40 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.