Linux kernel source tree
Go to file
David Howells ec03510e0a watch_queue: Fix lack of barrier/sync/lock between post and read
commit 2ed147f015 upstream.

There's nothing to synchronise post_one_notification() versus
pipe_read().  Whilst posting is done under pipe->rd_wait.lock, the
reader only takes pipe->mutex which cannot bar notification posting as
that may need to be made from contexts that cannot sleep.

Fix this by setting pipe->head with a barrier in post_one_notification()
and reading pipe->head with a barrier in pipe_read().

If that's not sufficient, the rd_wait.lock will need to be taken,
possibly in a ->confirm() op so that it only applies to notifications.
The lock would, however, have to be dropped before copy_page_to_iter()
is invoked.

Fixes: c73be61ced ("pipe: Add general notification queue support")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-16 14:16:02 +01:00
arch arm64: dts: marvell: armada-37xx: Remap IO space to bus address 0x0 2022-03-16 14:16:01 +01:00
block block/wbt: fix negative inflight counter when remove scsi device 2022-02-23 12:01:04 +01:00
certs certs: Trigger creation of RSA module signing key if it's not an RSA key 2021-09-15 09:50:29 +02:00
crypto crypto: api - Move cryptomgr soft dependency into algapi 2022-02-11 09:09:03 +01:00
Documentation arm64: cpufeature: add HWCAP for FEAT_RPRES 2022-03-11 12:11:51 +01:00
drivers virtio: acknowledge all features before access 2022-03-16 14:16:02 +01:00
fs watch_queue: Fix lack of barrier/sync/lock between post and read 2022-03-16 14:16:02 +01:00
include virtio: acknowledge all features before access 2022-03-16 14:16:02 +01:00
init bpf: Add kconfig knob for disabling unpriv bpf by default 2022-01-05 12:40:34 +01:00
ipc shm: extend forced shm destroy to support objects from several IPC nses 2021-12-01 09:19:10 +01:00
kernel watch_queue: Fix lack of barrier/sync/lock between post and read 2022-03-16 14:16:02 +01:00
lib lib/iov_iter: initialize "flags" in new pipe_buffer 2022-02-23 12:01:06 +01:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm memfd: fix F_SEAL_WRITE after shmem huge page allocated 2022-03-08 19:09:36 +01:00
net ipv6: prevent a possible race condition with lifetimes 2022-03-16 14:16:00 +01:00
samples ftrace/samples: Add missing prototypes direct functions 2022-01-11 15:25:00 +01:00
scripts kconfig: fix failing to generate auto.conf 2022-02-23 12:01:07 +01:00
security ima: Do not print policy rule with inactive LSM labels 2022-02-16 12:54:16 +01:00
sound ASoC: cs4265: Fix the duplicated control name 2022-03-08 19:09:35 +01:00
tools selftests/memfd: clean up mapping in mfd_fail_write 2022-03-16 14:16:01 +01:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:25:48 +01:00
virt KVM: eventfd: Fix false positive RCU usage warning 2022-02-16 12:54:20 +01:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.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 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 MAINTAINERS: adjust GCC PLUGINS after gcc-plugin.sh removal 2021-12-14 11:32:46 +01:00
Makefile Linux 5.10.105 2022-03-11 12:11:55 +01:00
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.