Messages in this thread Patch in this message | | | From | "Eric W. Biederman" <> | Subject | [PATCH 1/1] kernel/pid_namespace.c: Fixing a lack of cleanup (Probable resources leak). | Date | Tue, 5 Mar 2013 00:26:47 -0300 |
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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> --- kernel/pid_namespace.c | 16 +++++++++++----- 1 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index c1c3dc1..d94e4b6 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -37,7 +37,7 @@ static struct kmem_cache *pid_ns_cachep; * @nr_ids: the number of numerical ids this pid will have to carry */ -static struct kmem_cache *create_pid_cachep(int nr_ids) +static struct pid_cache *create_pid_cachep(int nr_ids) { struct pid_cache *pcache; struct kmem_cache *cachep; @@ -63,7 +63,7 @@ static struct kmem_cache *create_pid_cachep(int nr_ids) list_add(&pcache->list, &pid_caches_lh); out: mutex_unlock(&pid_caches_mutex); - return pcache->cachep; + return pcache; err_cachep: kfree(pcache); @@ -85,6 +85,7 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns struct pid_namespace *parent_pid_ns) { struct pid_namespace *ns; + struct pid_cache *pcache; unsigned int level = parent_pid_ns->level + 1; int i; int err; @@ -103,15 +104,16 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns if (!ns->pidmap[0].page) goto out_free; - ns->pid_cachep = create_pid_cachep(level + 1); - if (ns->pid_cachep == NULL) + pcache = create_pid_cachep(level + 1); + if (pcache == NULL) goto out_free_map; err = proc_alloc_inum(&ns->proc_inum); if (err) - goto out_free_map; + goto out_free_cachep; kref_init(&ns->kref); + ns->pid_cachep = pcache->cachep; ns->level = level; ns->parent = get_pid_ns(parent_pid_ns); ns->user_ns = get_user_ns(user_ns); @@ -126,6 +128,10 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns return ns; +out_free_cachep: + kmem_cache_destroy(pcache->cachep); + list_del(&pcache->list); + kfree(pcache); out_free_map: kfree(ns->pidmap[0].page); out_free: -- 1.7.2.5
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