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Ming Lei 747b654e40 blk-mq: clear stale request in tags->rq[] before freeing one request pool
[ Upstream commit bd63141d585bef14f4caf111f6d0e27fe2300ec6 ]

refcount_inc_not_zero() in bt_tags_iter() still may read one freed
request.

Fix the issue by the following approach:

1) hold a per-tags spinlock when reading ->rqs[tag] and calling
refcount_inc_not_zero in bt_tags_iter()

2) clearing stale request referred via ->rqs[tag] before freeing
request pool, the per-tags spinlock is held for clearing stale
->rq[tag]

So after we cleared stale requests, bt_tags_iter() won't observe
freed request any more, also the clearing will wait for pending
request reference.

The idea of clearing ->rqs[] is borrowed from John Garry's previous
patch and one recent David's patch.

Tested-by: John Garry <john.garry@huawei.com>
Reviewed-by: David Jeffery <djeffery@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210511152236.763464-4-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:55:58 +02:00
arch KVM: s390: get rid of register asm usage 2021-07-14 16:55:56 +02:00
block blk-mq: clear stale request in tags->rq[] before freeing one request pool 2021-07-14 16:55:58 +02:00
certs certs: Add ability to preload revocation certs 2021-06-30 08:47:30 -04:00
crypto crypto: shash - avoid comparing pointers to exported functions under CFI 2021-07-14 16:55:54 +02:00
Documentation hwmon: (max31790) Fix pwmX_enable attributes 2021-07-14 16:55:55 +02:00
drivers ACPI: EC: Make more Asus laptops use ECDT _GPE 2021-07-14 16:55:58 +02:00
fs block_dump: remove block_dump feature in mark_inode_dirty() 2021-07-14 16:55:58 +02:00
include media: Fix Media Controller API config checks 2021-07-14 16:55:56 +02:00
init sched/core: Initialize the idle task with preemption disabled 2021-07-14 16:55:50 +02:00
ipc ipc/mqueue, msg, sem: avoid relying on a stack reference past its expiry 2021-05-26 12:06:54 +02:00
kernel lockding/lockdep: Avoid to find wrong lock dep path in check_irq_usage() 2021-07-14 16:55:56 +02:00
lib lib: vsprintf: Fix handling of number field widths in vsscanf 2021-07-14 16:55:57 +02:00
LICENSES
mm mm/gup: fix try_grab_compound_head() race with split_huge_page() 2021-07-14 16:55:42 +02:00
net SUNRPC: Should wake up the privileged task firstly. 2021-07-14 16:55:42 +02:00
samples samples: vfio-mdev: fix error handing in mdpy_fb_probe() 2021-06-10 13:39:15 +02:00
scripts Makefile: fix GDB warning with CONFIG_RELR 2021-07-14 16:55:53 +02:00
security evm: Refuse EVM_ALLOW_METADATA_WRITES only if an HMAC key is loaded 2021-07-14 16:55:46 +02:00
sound ALSA: hda/realtek: fix mute/micmute LEDs for HP EliteBook 830 G8 Notebook PC 2021-07-14 16:55:37 +02:00
tools selftests/lkdtm: Avoid needing explicit sub-shell 2021-07-14 16:55:38 +02:00
usr
virt KVM: do not allow mapping valid but non-reference-counted pages 2021-06-30 08:47:25 -04:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING
CREDITS
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 f2fs: move ioctl interface definitions to separated file 2021-05-19 10:13:00 +02:00
Makefile Makefile: fix GDB warning with CONFIG_RELR 2021-07-14 16:55:53 +02:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
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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.