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Isaac J. Manjarres 50b21bba36 of: reserved_mem: Have kmemleak ignore dynamically allocated reserved mem 
commit ce4d9a1ea3 upstream.

Patch series "Fix kmemleak crashes when scanning CMA regions", v2.

When trying to boot a device with an ARM64 kernel with the following
config options enabled:

CONFIG_DEBUG_PAGEALLOC=y
CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT=y
CONFIG_DEBUG_KMEMLEAK=y

a crash is encountered when kmemleak starts to scan the list of gray
or allocated objects that it maintains. Upon closer inspection, it was
observed that these page-faults always occurred when kmemleak attempted
to scan a CMA region.

At the moment, kmemleak is made aware of CMA regions that are specified
through the devicetree to be dynamically allocated within a range of
addresses. However, kmemleak should not need to scan CMA regions or any
reserved memory region, as those regions can be used for DMA transfers
between drivers and peripherals, and thus wouldn't contain anything
useful for kmemleak.

Additionally, since CMA regions are unmapped from the kernel's address
space when they are freed to the buddy allocator at boot when
CONFIG_DEBUG_PAGEALLOC is enabled, kmemleak shouldn't attempt to access
those memory regions, as that will trigger a crash. Thus, kmemleak
should ignore all dynamically allocated reserved memory regions.


This patch (of 1):

Currently, kmemleak ignores dynamically allocated reserved memory regions
that don't have a kernel mapping.  However, regions that do retain a
kernel mapping (e.g.  CMA regions) do get scanned by kmemleak.

This is not ideal for two reasons:

1  kmemleak works by scanning memory regions for pointers to allocated
   objects to determine if those objects have been leaked or not.
   However, reserved memory regions can be used between drivers and
   peripherals for DMA transfers, and thus, would not contain pointers to
   allocated objects, making it unnecessary for kmemleak to scan these
   reserved memory regions.

2  When CONFIG_DEBUG_PAGEALLOC is enabled, along with kmemleak, the
   CMA reserved memory regions are unmapped from the kernel's address
   space when they are freed to buddy at boot.  These CMA reserved regions
   are still tracked by kmemleak, however, and when kmemleak attempts to
   scan them, a crash will happen, as accessing the CMA region will result
   in a page-fault, since the regions are unmapped.

Thus, use kmemleak_ignore_phys() for all dynamically allocated reserved
memory regions, instead of those that do not have a kernel mapping
associated with them.

Link: https://lkml.kernel.org/r/20230208232001.2052777-1-isaacmanjarres@google.com
Link: https://lkml.kernel.org/r/20230208232001.2052777-2-isaacmanjarres@google.com
Fixes: a7259df767 ("memblock: make memblock_find_in_range method private")
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Kirill A. Shutemov <kirill.shtuemov@linux.intel.com>
Cc: Nick Kossifidis <mick@ics.forth.gr>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: Saravana Kannan <saravanak@google.com>
Cc: <stable@vger.kernel.org>	[5.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2023-02-22 12:59:46 +01:00
arch s390/decompressor: specify __decompress() buf len to avoid overflow 2023-02-22 12:59:43 +01:00
block block, bfq: fix uaf for bfqq in bic_set_bfqq() 2023-02-09 11:28:06 +01:00
certs certs: Fix build error when PKCS#11 URI contains semicolon 2023-02-09 11:28:11 +01:00
crypto use less confusing names for iov_iter direction initializers 2023-02-09 11:28:04 +01:00
Documentation Documentation/hw-vuln: Add documentation for Cross-Thread Return Predictions 2023-02-14 19:11:56 +01:00
drivers of: reserved_mem: Have kmemleak ignore dynamically allocated reserved mem 2023-02-22 12:59:46 +01:00
fs ceph: blocklist the kclient when receiving corrupted snap trace 2023-02-22 12:59:45 +01:00
include ceph: move mount state enum to super.h 2023-02-22 12:59:45 +01:00
init gcc: disable -Warray-bounds for gcc-11 too 2023-01-14 10:33:43 +01:00
io_uring use less confusing names for iov_iter direction initializers 2023-02-09 11:28:04 +01:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel rtmutex: Ensure that the top waiter is always woken up 2023-02-14 19:11:54 +01:00
lib maple_tree: fix mas_empty_area_rev() lower bound validation 2023-02-09 11:28:23 +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 Fix page corruption caused by racy check in __free_pages 2023-02-14 19:11:54 +01:00
net net: sched: sch: Bounds check priority 2023-02-22 12:59:43 +01:00
rust rust: print: avoid evaluating arguments in pr_* macros in unsafe blocks 2023-02-06 08:06:34 +01:00
samples ftrace: Export ftrace_free_filter() to modules 2023-02-01 08:34:37 +01:00
scripts kbuild: modinst: Fix build error when CONFIG_MODULE_SIG_KEY is a PKCS#11 URI 2023-02-09 11:28:11 +01:00
security use less confusing names for iov_iter direction initializers 2023-02-09 11:28:04 +01:00
sound ASoC: cs42l56: fix DT probe 2023-02-22 12:59:42 +01:00
tools selftests: mptcp: userspace: fix v4-v6 test in v6.1 2023-02-22 12:59:45 +01:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt kvm/vfio: Fix potential deadlock on vfio group_lock 2023-02-01 08:34:36 +01:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS panic: Expose "warn_count" to sysfs 2023-01-24 07:24:41 +01:00
Makefile Linux 6.1.12 2023-02-14 19:11:56 +01:00
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.