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Sean Christopherson 249e5e5a50 KVM: rseq: Update rseq when processing NOTIFY_RESUME on xfer to KVM guest
commit 8646e53633f314e4d746a988240d3b951a92f94a upstream.

Invoke rseq's NOTIFY_RESUME handler when processing the flag prior to
transferring to a KVM guest, which is roughly equivalent to an exit to
userspace and processes many of the same pending actions.  While the task
cannot be in an rseq critical section as the KVM path is reachable only
by via ioctl(KVM_RUN), the side effects that apply to rseq outside of a
critical section still apply, e.g. the current CPU needs to be updated if
the task is migrated.

Clearing TIF_NOTIFY_RESUME without informing rseq can lead to segfaults
and other badness in userspace VMMs that use rseq in combination with KVM,
e.g. due to the CPU ID being stale after task migration.

Fixes: 72c3c0fe54 ("x86/kvm: Use generic xfer to guest work function")
Reported-by: Peter Foley <pefoley@google.com>
Bisected-by: Doug Evans <dje@google.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210901203030.1292304-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[sean: Resolve benign conflict due to unrelated access_ok() check in 5.10]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06 15:55:49 +02:00
arch KVM: nVMX: Filter out all unsupported controls when eVMCS was activated 2021-10-06 15:55:49 +02:00
block blk-cgroup: fix UAF by grabbing blkcg lock before destroying blkg pd 2021-09-30 10:11:07 +02:00
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: sm2 - fix a memory leak in sm2 2021-07-14 16:56:06 +02:00
Documentation dt-bindings: mtd: gpmc: Fix the ECC bytes vs. OOB bytes equation 2021-09-22 12:27:59 +02:00
drivers scsi: ufs: Fix illegal offset in UPIU event trace 2021-10-06 15:55:48 +02:00
fs fs-verity: fix signed integer overflow with i_size near S64_MAX 2021-10-06 15:55:46 +02:00
include compiler.h: Introduce absolute_pointer macro 2021-09-30 10:11:07 +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 KVM: rseq: Update rseq when processing NOTIFY_RESUME on xfer to KVM guest 2021-10-06 15:55:49 +02:00
lib treewide: Change list_sort to use const pointers 2021-09-30 10:11:04 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm: fix uninitialized use in overcommit_policy_handler 2021-09-30 10:10:58 +02:00
net mac80211: fix use-after-free in CCMP/GCMP RX 2021-10-06 15:55:48 +02:00
samples samples: bpf: Fix tracex7 error raised on the missing argument 2021-09-18 13:40:23 +02:00
scripts gen_compile_commands: fix missing 'sys' package 2021-09-22 12:27:58 +02:00
security Smack: Fix wrong semantics in smk_access_entry() 2021-09-18 13:40:18 +02:00
sound ALSA: hda/realtek: Quirks to enable speaker output for Lenovo Legion 7i 15IMHG05, Yoga 7i 14ITL5/15ITL5, and 13s Gen2 laptops. 2021-10-06 15:55:46 +02:00
tools kselftest/arm64: signal: Skip tests if required features are missing 2021-09-30 10:11:03 +02:00
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: Do not leak memory for duplicate debugfs directories 2021-08-12 13:22:17 +02:00
.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 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 f2fs: move ioctl interface definitions to separated file 2021-05-19 10:13:00 +02:00
Makefile Linux 5.10.70 2021-09-30 10:11:08 +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.