shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-08 11:50:43 +09:00
Code Issues Packages Projects Releases Wiki Activity

mempolicy: fix refcount leak in mpol_set_shared_policy()

Browse Source 
commit 63f74ca21f upstream.

When shared_policy_replace() fails to allocate new->policy is not freed
correctly by mpol_set_shared_policy().  The problem is that shared
mempolicy code directly call kmem_cache_free() in multiple places where
it is easy to make a mistake.

This patch creates an sp_free wrapper function and uses it. The bug was
introduced pre-git age (IOW, before 2.6.12-rc2).

[mgorman@suse.de: Editted changelog]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Christoph Lameter <cl@linux.com>
Cc: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
KOSAKI Motohiro
2012-10-08 16:29:19 -07:00
committed by Greg Kroah-Hartman
parent cedd186e31
commit 29715fe22f
1 changed files with 9 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
mm/mempolicy.c
View File

@@ -2095,12 +2095,17 @@ mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
return pol;
}
static void sp_free(struct sp_node *n)
{
mpol_put(n->policy);
kmem_cache_free(sn_cache, n);
}
static void sp_delete(struct shared_policy *sp, struct sp_node *n)
{
pr_debug("deleting %lx-l%lx\n", n->start, n->end);
rb_erase(&n->nd, &sp->root);
mpol_put(n->policy);
kmem_cache_free(sn_cache, n);
sp_free(n);
}
static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
@@ -2239,7 +2244,7 @@ int mpol_set_shared_policy(struct shared_policy *info,
}
err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
if (err && new)
kmem_cache_free(sn_cache, new);
sp_free(new);
return err;
}
@@ -2256,9 +2261,7 @@ void mpol_free_shared_policy(struct shared_policy *p)
while (next) {
n = rb_entry(next, struct sp_node, nd);
next = rb_next(&n->nd);
rb_erase(&n->nd, &p->root);
mpol_put(n->policy);
kmem_cache_free(sn_cache, n);
sp_delete(p, n);
}
mutex_unlock(&p->mutex);
}