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Bob Peterson 42fd500353 gfs2: Don't skip dlm unlock if glock has an lvb
commit 78178ca844f0eb88f21f31c7fde969384be4c901 upstream.

Patch fb6791d100 was designed to allow gfs2 to unmount quicker by
skipping the step where it tells dlm to unlock glocks in EX with lvbs.
This was done because when gfs2 unmounts a file system, it destroys the
dlm lockspace shortly after it destroys the glocks so it doesn't need to
unlock them all: the unlock is implied when the lockspace is destroyed
by dlm.

However, that patch introduced a use-after-free in dlm: as part of its
normal dlm_recoverd process, it can call ls_recovery to recover dead
locks. In so doing, it can call recover_rsbs which calls recover_lvb for
any mastered rsbs. Func recover_lvb runs through the list of lkbs queued
to the given rsb (if the glock is cached but unlocked, it will still be
queued to the lkb, but in NL--Unlocked--mode) and if it has an lvb,
copies it to the rsb, thus trying to preserve the lkb. However, when
gfs2 skips the dlm unlock step, it frees the glock and its lvb, which
means dlm's function recover_lvb references the now freed lvb pointer,
copying the freed lvb memory to the rsb.

This patch changes the check in gdlm_put_lock so that it calls
dlm_unlock for all glocks that contain an lvb pointer.

Fixes: fb6791d100 ("GFS2: skip dlm_unlock calls in unmount")
Cc: stable@vger.kernel.org # v3.8+
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-04 11:38:43 +01:00
arch sparc32: fix a user-triggerable oops in clear_user() 2021-03-04 11:38:43 +01:00
block blk-settings: align max_sectors on "logical_block_size" boundary 2021-03-04 11:38:22 +01:00
certs certs: Fix blacklist flag type confusion 2021-03-04 11:37:59 +01:00
crypto crypto: michael_mic - fix broken misalignment handling 2021-03-04 11:38:31 +01:00
Documentation mm/vmscan: restore zone_reclaim_mode ABI 2021-03-04 11:38:38 +01:00
drivers spi: spi-synquacer: fix set_cs handling 2021-03-04 11:38:43 +01:00
fs gfs2: Don't skip dlm unlock if glock has an lvb 2021-03-04 11:38:43 +01:00
include kcmp: Support selection of SYS_kcmp without CHECKPOINT_RESTORE 2021-03-04 11:38:41 +01:00
init kcmp: Support selection of SYS_kcmp without CHECKPOINT_RESTORE 2021-03-04 11:38:41 +01:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel kcmp: Support selection of SYS_kcmp without CHECKPOINT_RESTORE 2021-03-04 11:38:41 +01:00
lib udp: fix skb_copy_and_csum_datagram with odd segment sizes 2021-02-17 11:02:28 +01:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm, compaction: make fast_isolate_freepages() stay within zone 2021-03-04 11:38:38 +01:00
net svcrdma: Hold private mutex while invoking rdma_accept() 2021-03-04 11:38:08 +01:00
samples watch_queue: Drop references to /dev/watch_queue 2021-03-04 11:37:59 +01:00
scripts scripts/recordmcount.pl: support big endian for ARCH sh 2021-02-26 10:13:02 +01:00
security KEYS: trusted: Reserve TPM for seal and unseal operations 2021-03-04 11:38:29 +01:00
sound ASoC: siu: Fix build error by a wrong const prefix 2021-03-04 11:38:28 +01:00
tools kcmp: Support selection of SYS_kcmp without CHECKPOINT_RESTORE 2021-03-04 11:38:41 +01:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM: Use kvm_pfn_t for local PFN variable in hva_to_pfn_remapped() 2021-02-26 10:13:01 +01:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.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: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-12-10 15:30:13 -08:00
Makefile Linux 5.10.19 2021-02-26 10:14:35 +01:00
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.