Odin Ugedal 2407794f22 cgroup: fix psi monitor for root cgroup ... commit 385aac1519417b89cb91b77c22e4ca21db563cd0 upstream. Fix NULL pointer dereference when adding new psi monitor to the root cgroup. PSI files for root cgroup was introduced in df5ba5be74 by using system wide psi struct when reading, but file write/monitor was not properly fixed. Since the PSI config for the root cgroup isn't initialized, the current implementation tries to lock a NULL ptr, resulting in a crash. Can be triggered by running this as root: $ tee /sys/fs/cgroup/cpu.pressure <<< "some 10000 1000000" Signed-off-by: Odin Ugedal <odin@uged.al> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Dan Schatzberg <dschatzberg@fb.com> Fixes: df5ba5be74 ("kernel/sched/psi.c: expose pressure metrics on root cgroup") Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: stable@vger.kernel.org # 5.2+ Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-02-17 10:35:14 +01:00
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Makefile	cgroup: cgroup v2 freezer	2019-04-19 11:26:48 -07:00
cgroup-internal.h	cgroup: make TRACE_CGROUP_PATH irq-safe	2019-04-19 11:26:49 -07:00
cgroup-v1.c	cgroup: Fix memory leak when parsing multiple source parameters	2021-01-06 14:48:37 +01:00
cgroup.c	cgroup: fix psi monitor for root cgroup	2021-02-17 10:35:14 +01:00
cpuset.c	cpuset: fix race between hotplug work and later CPU offline	2020-12-30 11:51:36 +01:00
debug.c	kernel: cgroup: fix misuse of %x	2019-05-06 08:47:48 -07:00
freezer.c	cgroup: freezer: don't change task and cgroups status unnecessarily	2019-12-31 16:45:06 +01:00
legacy_freezer.c	cgroup: rename freezer.c into legacy_freezer.c	2019-04-19 11:26:48 -07:00
namespace.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
pids.c	cgroup: pids: use atomic64_t for pids->limit	2019-12-17 19:56:15 +01:00
rdma.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 451	2019-06-19 17:09:08 +02:00
rstat.c	Revert "cgroup: Add memory barriers to plug cgroup_rstat_updated() race window"	2020-06-07 13:18:46 +02:00