tree da525ae676d3794ff05ff7cdb9fbf2a74ca65066
parent d07e75a6e0e8582bdecefe8868b0bfbdf2ee7085
author Gerald Schaefer <gerald.schaefer@de.ibm.com> 1369411669 +0200
committer Ingo Molnar <mingo@kernel.org> 1369726822 +0200

sched/autogroup: Fix race with task_groups list

In autogroup_create(), a tg is allocated and added to the task_groups
list. If CONFIG_RT_GROUP_SCHED is set, this tg is then modified while on
the list, without locking. This can race with someone walking the list,
like __enable_runtime() during CPU unplug, and result in a use-after-free
bug.

To fix this, move sched_online_group(), which adds the tg to the list,
to the end of the autogroup_create() function after the modification.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1369411669-46971-2-git-send-email-gerald.schaefer@de.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>