diff options
| author | Jing-Ting Wu <[email protected]> | 2022-08-23 13:41:46 +0800 |
|---|---|---|
| committer | Tejun Heo <[email protected]> | 2022-08-23 08:11:06 -1000 |
| commit | 763f4fb76e24959c370cdaa889b2492ba6175580 (patch) | |
| tree | 541e52a6ef13de29f061d5a3a90eedabb4938e5f | |
| parent | 4f7e7236435ca0abe005c674ebd6892c6e83aeb3 (diff) | |
cgroup: Fix race condition at rebind_subsystems()
Root cause:
The rebind_subsystems() is no lock held when move css object from A
list to B list,then let B's head be treated as css node at
list_for_each_entry_rcu().
Solution:
Add grace period before invalidating the removed rstat_css_node.
Reported-by: Jing-Ting Wu <[email protected]>
Suggested-by: Michal Koutný <[email protected]>
Signed-off-by: Jing-Ting Wu <[email protected]>
Tested-by: Jing-Ting Wu <[email protected]>
Link: https://lore.kernel.org/linux-arm-kernel/[email protected]/T/
Acked-by: Mukesh Ojha <[email protected]>
Fixes: a7df69b81aac ("cgroup: rstat: support cgroup1")
Cc: [email protected] # v5.13+
Signed-off-by: Tejun Heo <[email protected]>
| -rw-r--r-- | kernel/cgroup/cgroup.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index e1387499b336..e4bb5d57f4d1 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -1820,6 +1820,7 @@ int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask) if (ss->css_rstat_flush) { list_del_rcu(&css->rstat_css_node); + synchronize_rcu(); list_add_rcu(&css->rstat_css_node, &dcgrp->rstat_css_list); } |