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Filename Latest commit message Latest commit date
Mike Kravetz 8c07792e79 hugetlb: check for undefined shift on 32 bit architectures
commit ec4288fe63966b26d53907212ecd05dfa81dd2cc upstream.

Users can specify the hugetlb page size in the mmap, shmget and
memfd_create system calls.  This is done by using 6 bits within the flags
argument to encode the base-2 logarithm of the desired page size.  The
routine hstate_sizelog() uses the log2 value to find the corresponding
hugetlb hstate structure.  Converting the log2 value (page_size_log) to
potential hugetlb page size is the simple statement:

	1UL << page_size_log

Because only 6 bits are used for page_size_log, the left shift can not be
greater than 63.  This is fine on 64 bit architectures where a long is 64
bits.  However, if a value greater than 31 is passed on a 32 bit
architecture (where long is 32 bits) the shift will result in undefined
behavior.  This was generally not an issue as the result of the undefined
shift had to exactly match hugetlb page size to proceed.

Recent improvements in runtime checking have resulted in this undefined
behavior throwing errors such as reported below.

Fix by comparing page_size_log to BITS_PER_LONG before doing shift.

Link: https://lkml.kernel.org/r/20230216013542.138708-1-mike.kravetz@oracle.com
Link: https://lore.kernel.org/lkml/CA+G9fYuei_Tr-vN9GS7SfFyU1y9hNysnf=PB7kT0=yv4MiPgVg@mail.gmail.com/
Fixes: 42d7395feb ("mm: support more pagesizes for MAP_HUGETLB/SHM_HUGETLB")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reviewed-by: Jesper Juhl <jesperjuhl76@gmail.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:39 +01:00
arch s390/decompressor: specify __decompress() buf len to avoid overflow 2023-02-22 12:50:34 +01:00
block blk-cgroup: fix missing pd_online_fn() while activating policy 2023-02-06 07:52:48 +01:00
certs
crypto crypto: tcrypt - Fix multibuffer skcipher speed test mem leak 2023-01-18 11:41:19 +01:00
Documentation docs: Fix path paste-o for /sys/kernel/warn_count 2023-02-06 07:52:50 +01:00
drivers mmc: mmc_spi: fix error handling in mmc_spi_probe() 2023-02-22 12:50:39 +01:00
fs xfs: sync lazy sb accounting on quiesce of read-only mounts 2023-02-22 12:50:38 +01:00
include hugetlb: check for undefined shift on 32 bit architectures 2023-02-22 12:50:39 +01:00
init init/Kconfig: fix CC_HAS_ASM_GOTO_TIED_OUTPUT test with dash 2022-12-08 11:22:59 +01:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2022-12-08 11:23:06 +01:00
kernel sched/psi: Fix use-after-free in ep_remove_wait_queue() 2023-02-22 12:50:39 +01:00
lib netlink: prevent potential spectre v1 gadgets 2023-02-06 07:52:45 +01:00
LICENSES
mm migrate: hugetlb: check for hugetlb shared PMD in node migration 2023-02-22 12:50:34 +01:00
net ipv4: Fix incorrect route flushing when source address is deleted 2023-02-22 12:50:38 +01:00
samples samples: vfio-mdev: Fix missing pci_disable_device() in mdpy_fb_probe() 2023-01-18 11:41:26 +01:00
scripts ftrace/scripts: Update the instructions for ftrace-bisect.sh 2023-02-06 07:52:44 +01:00
security tomoyo: fix broken dependency on *.conf.default 2023-02-06 07:52:35 +01:00
sound ALSA: hda/realtek - fixed wrong gpio assigned 2023-02-22 12:50:39 +01:00
tools Revert "ipv4: Fix incorrect route flushing when source address is deleted" 2023-02-22 12:50:38 +01:00
usr
virt KVM: arm64: vgic: Fix exit condition in scan_its_table() 2022-10-29 10:20:35 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS net/phy/mdio-i2c: Move header file to include/linux/mdio 2023-02-06 07:52:46 +01:00
Makefile Linux 5.4.231 2023-02-06 07:52:51 +01:00
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.