linux-stable

Go to file

Lorenzo Stoakes 61765a1194 mm/mempolicy: correctly update prev when policy is equal on mbind commit `00ca0f2e86` upstream. The refactoring in commit `f4e9e0e694` ("mm/mempolicy: fix use-after-free of VMA iterator") introduces a subtle bug which arises when attempting to apply a new NUMA policy across a range of VMAs in mbind_range(). The refactoring passes a **prev pointer to keep track of the previous VMA in order to reduce duplication, and in all but one case it keeps this correctly updated. The bug arises when a VMA within the specified range has an equivalent policy as determined by mpol_equal() - which unlike other cases, does not update prev. This can result in a situation where, later in the iteration, a VMA is found whose policy does need to change. At this point, vma_merge() is invoked with prev pointing to a VMA which is before the previous VMA. Since vma_merge() discovers the curr VMA by looking for the one immediately after prev, it will now be in a situation where this VMA is incorrect and the merge will not proceed correctly. This is checked in the VM_WARN_ON() invariant case with end > curr->vm_end, which, if a merge is possible, results in a warning (if CONFIG_DEBUG_VM is specified). I note that vma_merge() performs these invariant checks only after merge_prev/merge_next are checked, which is debatable as it hides this issue if no merge is possible even though a buggy situation has arisen. The solution is simply to update the prev pointer even when policies are equal. This caused a bug to arise in the 6.2.y stable tree, and this patch resolves this bug. Link: https://lkml.kernel.org/r/83f1d612acb519d777bebf7f3359317c4e7f4265.1682866629.git.lstoakes@gmail.com Fixes: `f4e9e0e694` ("mm/mempolicy: fix use-after-free of VMA iterator") Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Reported-by: kernel test robot <oliver.sang@intel.com> Link: https://lore.kernel.org/oe-lkp/202304292203.44ddeff6-oliver.sang@intel.com Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Mel Gorman <mgorman@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-05-11 23:11:35 +09:00
Documentation	ASoC: dt-bindings: qcom,lpass-rx-macro: correct minItems for clocks	2023-05-11 23:10:55 +09:00
LICENSES	…
arch	ia64: fix an addr to taddr in huge_pte_offset()	2023-05-11 23:11:35 +09:00
block	blk-mq: don't plug for head insertions in blk_execute_rq_nowait	2023-05-11 23:11:14 +09:00
certs	…
crypto	crypto: drbg - Only fail when jent is unavailable in FIPS mode	2023-05-11 23:11:12 +09:00
drivers	s390/dasd: fix hanging blockdevice after request requeue	2023-05-11 23:11:35 +09:00
fs	btrfs: scrub: reject unsupported scrub flags	2023-05-11 23:11:34 +09:00
include	btrfs: scrub: reject unsupported scrub flags	2023-05-11 23:11:34 +09:00
init	…
io_uring	io_uring/rsrc: use nospec'ed indexes	2023-05-11 23:11:15 +09:00
ipc	…
kernel	kcsan: Avoid READ_ONCE() in read_instrumented_memory()	2023-05-11 23:11:34 +09:00
lib	debugobject: Prevent init race with static objects	2023-05-11 23:11:07 +09:00
mm	mm/mempolicy: correctly update prev when policy is equal on mbind	2023-05-11 23:11:35 +09:00
net	SUNRPC: remove the maximum number of retries in call_bind_status	2023-05-11 23:11:29 +09:00
rust	…
samples	…
scripts	scripts/gdb: fix lx-timerlist for Python3	2023-05-11 23:11:34 +09:00
security	selinux: ensure av_permissions.h is built when needed	2023-05-11 23:10:56 +09:00
sound	ALSA: hda/realtek: Fix mute and micmute LEDs for an HP laptop	2023-05-11 23:11:33 +09:00
tools	tracing/user_events: Ensure write index cannot be negative	2023-05-11 23:11:25 +09:00
usr	…
virt	…
.clang-format	…
.cocciconfig	…
.get_maintainer.ignore	…
.gitattributes	…
.gitignore	…
.mailmap	…
.rustfmt.toml	…
COPYING	…
CREDITS	…
Kbuild	…
Kconfig	…
MAINTAINERS	…
Makefile	Linux 6.2.14	2023-05-01 08:29:23 +09:00
README	…

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.