Messages in this thread | | | Subject | Re: [PATCH] ima: fix infinite loop within "ima_match_policy" function. | From | Mimi Zohar <> | Date | Mon, 23 Aug 2021 07:22:52 -0400 |
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Hi Liqiong,
On Mon, 2021-08-23 at 11:04 +0800, 李力琼 wrote: > Hi Mimi : > > The situation is a little different,'list_splice_init_rcu' > don't change the list head. If "ima_rules" being changed, > readers may can't reload the new value in time for cpu cache > or compiler optimization. Defining "ima_rules" as a volatile > variable can fix, but It is inefficient.
After looking at list_splice_tail_init_rcu() some more, it is actually making sure there aren't any readers traversing "ima_temp_rules", not "ima_policy_rules". There aren't any readers traversing "ima_temp_rules".
> > Maybe using a temporary ima_rules variable for every > "list_for_each_entry_rcu(entry, ima_rules, list)" loop is > a better solution to fix the "endless loop" bug.
Agreed
thanks,
Mimi
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