android_kernel_motorola_sm6375/kernel/sched
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Cyril Hrubis d2fc4134aa sched/rt: Disallow writing invalid values to sched_rt_period_us
commit 079be8fc630943d9fc70a97807feb73d169ee3fc upstream.

The validation of the value written to sched_rt_period_us was broken
because:

  - the sysclt_sched_rt_period is declared as unsigned int
  - parsed by proc_do_intvec()
  - the range is asserted after the value parsed by proc_do_intvec()

Because of this negative values written to the file were written into a
unsigned integer that were later on interpreted as large positive
integers which did passed the check:

  if (sysclt_sched_rt_period <= 0)
	return EINVAL;

This commit fixes the parsing by setting explicit range for both
perid_us and runtime_us into the sched_rt_sysctls table and processes
the values with proc_dointvec_minmax() instead.

Alternatively if we wanted to use full range of unsigned int for the
period value we would have to split the proc_handler and use
proc_douintvec() for it however even the
Documentation/scheduller/sched-rt-group.rst describes the range as 1 to
INT_MAX.

As far as I can tell the only problem this causes is that the sysctl
file allows writing negative values which when read back may confuse
userspace.

There is also a LTP test being submitted for these sysctl files at:

  http://patchwork.ozlabs.org/project/ltp/patch/20230901144433.2526-1-chrubis@suse.cz/

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20231002115553.3007-2-chrubis@suse.cz
[ pvorel: rebased for 5.4 ]
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-01 13:13:33 +01:00
..
autogroup.c
autogroup.h
clock.c
completion.c
core.c sched_getaffinity: don't assume 'cpumask_size()' is fully initialized 2023-04-05 11:16:42 +02:00
cpuacct.c
cpudeadline.c
cpudeadline.h
cpufreq.c
cpufreq_schedutil.c
cpupri.c
cpupri.h
cputime.c
deadline.c sched/deadline,rt: Remove unused parameter from pick_next_[rt|dl]_entity() 2023-03-11 16:43:35 +01:00
debug.c
fair.c sched/fair: Don't balance task to its current running CPU 2023-07-27 08:37:42 +02:00
features.h sched/rt: Disable RT_RUNTIME_SHARE by default 2022-07-21 20:59:18 +02:00
idle.c
isolation.c
loadavg.c
Makefile
membarrier.c sched/membarrier: reduce the ability to hammer on sys_membarrier 2024-02-23 08:25:14 +01:00
pelt.c
pelt.h
psi.c sched/psi: Fix use-after-free in ep_remove_wait_queue() 2023-02-22 12:50:39 +01:00
rt.c sched/rt: Disallow writing invalid values to sched_rt_period_us 2024-03-01 13:13:33 +01:00
sched-pelt.h
sched.h
stats.c
stats.h
stop_task.c
swait.c
topology.c
wait.c list: add "list_del_init_careful()" to go with "list_empty_careful()" 2023-06-28 10:18:35 +02:00
wait_bit.c