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Alex Williamson 5321908ef7 vfio/type1: Unpin zero pages
commit 873aefb376 upstream.

There's currently a reference count leak on the zero page.  We increment
the reference via pin_user_pages_remote(), but the page is later handled
as an invalid/reserved page, therefore it's not accounted against the
user and not unpinned by our put_pfn().

Introducing special zero page handling in put_pfn() would resolve the
leak, but without accounting of the zero page, a single user could
still create enough mappings to generate a reference count overflow.

The zero page is always resident, so for our purposes there's no reason
to keep it pinned.  Therefore, add a loop to walk pages returned from
pin_user_pages_remote() and unpin any zero pages.

Cc: stable@vger.kernel.org
Reported-by: Luboslav Pivarc <lpivarc@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/166182871735.3518559.8884121293045337358.stgit@omen
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-15 11:30:02 +02:00
arch arm64: cacheinfo: Fix incorrect assignment of signed error value to unsigned fw_level 2022-09-15 11:30:01 +02:00
block blk-mq: fix io hung due to missing commit_rqs 2022-08-31 17:16:50 +02:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:22:01 +02:00
crypto KEYS: asymmetric: enforce SM2 signature use pkey algo 2022-08-17 14:24:28 +02:00
Documentation arm64: errata: Add Cortex-A510 to the repeat tlbi list 2022-09-05 10:30:04 +02:00
drivers vfio/type1: Unpin zero pages 2022-09-15 11:30:02 +02:00
fs btrfs: zoned: set pseudo max append zone limit in zone emulation mode 2022-09-15 11:30:02 +02:00
include fs: only do a memory barrier for the first set_buffer_uptodate() 2022-09-15 11:30:00 +02:00
init stack: Declare {randomize_,}kstack_offset to fix Sparse warnings 2022-08-17 14:23:10 +02:00
ipc ipc/mqueue: use get_tree_nodev() in mqueue_get_tree() 2022-06-09 10:23:10 +02:00
kernel tracing: Fix to check event_mutex is held while accessing trigger list 2022-09-15 11:30:02 +02:00
lib crypto: lib - remove unneeded selection of XOR_BLOCKS 2022-09-05 10:30:03 +02:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm Revert "mm: kmemleak: take a full lowmem check in kmemleak_*_phys()" 2022-09-15 11:30:00 +02:00
net net/core/skbuff: Check the return value of skb_copy_bits() 2022-09-15 11:30:01 +02:00
samples samples/landlock: Format with clang-format 2022-06-09 10:23:23 +02:00
scripts kbuild: fix up permissions on scripts/pahole-flags.sh 2022-09-08 12:30:36 +02:00
security apparmor: Fix memleak in aa_simple_write_to_buffer() 2022-08-25 11:40:01 +02:00
sound ALSA: usb-audio: Fix an out-of-bounds bug in __snd_usb_parse_audio_interface() 2022-09-15 11:30:02 +02:00
tools testing: selftests: nft_flowtable.sh: use random netns names 2022-09-05 10:30:12 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:27:15 +01:00
virt KVM: Unconditionally get a ref to /dev/kvm module when creating a VM 2022-08-25 11:39:53 +02:00
.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 mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
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 Input: goodix - add a goodix.h header file 2022-07-12 16:34:51 +02:00
Makefile Linux 5.15.67 2022-09-08 12:32:54 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.