Commit-ID: 41261b6a832ea0e788627f6a8707854423f9ff49 Gitweb: http://git.kernel.org/tip/41261b6a832ea0e788627f6a8707854423f9ff49 Author: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx> AuthorDate: Fri, 24 May 2013 18:07:49 +0200 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Tue, 28 May 2013 09:40:22 +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@xxxxxxxxxx> Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/1369411669-46971-2-git-send-email-gerald.schaefer@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- kernel/sched/auto_group.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/kernel/sched/auto_group.c b/kernel/sched/auto_group.c index 64de5f8..4a07353 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: -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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