diff options
| author | Gerald Schaefer <gerald.schaefer@de.ibm.com> | 2014-03-26 12:37:47 +0530 |
|---|---|---|
| committer | Eli Qiao <taget@linux.vnet.ibm.com> | 2014-03-31 13:50:57 +0800 |
| commit | 19da3e46931fa15713c0503720f567c2b8d8ff2b (patch) | |
| tree | b592ed65eb1dff582e677f737ff2a93cb5f2121e | |
| parent | f2043fc9c0847bf8c70892c48c5b70b2b6743a67 (diff) | |
| download | powerkvm-19da3e46931fa15713c0503720f567c2b8d8ff2b.tar.gz | |
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>
Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
(cherry picked from commit 41261b6a832ea0e788627f6a8707854423f9ff49)
| -rw-r--r-- | kernel/sched/auto_group.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/kernel/sched/auto_group.c b/kernel/sched/auto_group.c index 64de5f8b0c9ed..4a073539c58e6 100644 --- a/kernel/sched/auto_group.c +++ b/kernel/sched/auto_group.c @@ -77,8 +77,6 @@ static inline struct autogroup *autogroup_create(void) if (IS_ERR(tg)) goto out_free; - sched_online_group(tg, &root_task_group); - kref_init(&ag->kref); init_rwsem(&ag->lock); ag->id = atomic_inc_return(&autogroup_seq_nr); @@ -98,6 +96,7 @@ static inline struct autogroup *autogroup_create(void) #endif tg->autogroup = ag; + sched_online_group(tg, &root_task_group); return ag; out_free: |