Messages in this thread | | | Date | Fri, 10 May 2013 10:08:14 +0800 | From | Chen Gang <> | Subject | Re: [PATCH v2] kernel: audit_tree: resource management: need put_tree and goto Err when failure occures |
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On 05/10/2013 04:11 AM, Andrew Morton wrote: >> > But we need let 'rule->tree = NULL;' firstly, so can protect rule itself freed in kill_rules(). > I'll believe you ;) I turned this into a proper patch and added your > (missed) Signed-off-by:. >
Thanks.
At least, let 'rule->tree = NULL;' can:
a. it matches 'rule->tree = tree;' which is before successful return. also can make 'if (list_empty(&rule->rlist))' reasonable.
b. protect rule itself freed in kill_rules(), if it could happen. just like all 'rule->tree = NULL;' in audit_remove_tree_rule().
c. it will no negative effect.
>> > For me, after 'rule->tree = NULL', all things seems fine !! > Well, what was wrong before? Is there some user-triggerable > misbehaviour which you observed? If so, please describe it. > > >
I think, it will cause issue (randomly): if when we are using auditctl to add rule to monitor one file, and at the same time, the other user is just deleting this file.
I guess, it is why original code need 'if (list_empty(&rule->rlist))' after lock 'audit_filter_mutex' again.
Currently, I am just testing for it (and should give a test), and I will send the test plan and test result within this week (2013-05-12).
Thanks.
-- Chen Gang
Asianux Corporation
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