Messages in this thread | | | Date | Tue, 5 Mar 2013 02:04:45 -0300 | Subject | Re: [PATCH 1/1] kernel/pid_namespace.c: Fixing a lack of cleanup (Probable resources leak). | From | Raphael S Carvalho <> |
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On Tue, Mar 5, 2013 at 12:51 AM, Gao feng <gaofeng@cn.fujitsu.com> wrote: > On 2013/03/05 11:26, Eric W. Biederman wrote: >> From: Raphael S.Carvalho <raphael.scarv@gmail.com> >> >> Starting point: create_pid_namespace() >> >> Suppose create_pid_cachep() was executed sucessfully, thus: >> pcache was allocated by kmalloc(). >> cachep received a cache created by kmem_cache_create(). >> and pcache->list was added to the list pid_caches_lh. >> >> So what would happen if proc_alloc_inum() returns an error? >> The resources allocated by create_pid_namespace() would be deallocated! >> How about those resources allocated by create_pid_cachep()? >> By knowing that, I created this patch in order to fix that! >> >> Signed-off-by: Raphael S.Carvalho <raphael.scarv@gmail.com> >> --- > > Actually I noticed this problem and I think it is not a BUG. > Since the pid_cache is created for all pid namespace which have the same level. > Even this pid namespace is failed to create, the pid_cache will not be leaked, Other > pid namespace which has the same level will use the pid_cache and no need to > allocate it again. In other words, the pid_cache for every level pid namespace will > only be created once. > > I also think this patch add a bug,because there may be other pid namespace's pid_cachep > points to the same pid_cache which will be free at the by label out_free_cachep. >
Yeah, I found the snippet of code which searches for the pcache with the same level. 46 list_for_each_entry(pcache, &pid_caches_lh, list) 47 if (pcache->nr_ids == nr_ids) 48 goto out;
Regards, Raphael S.Carvalho
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