[Devel] [PATCH] Fix memory leak in inet_hashtables.h when NUMA is on

Pavel Emelyanov xemul at openvz.org
Fri Nov 23 08:13:11 PST 2007


The inet_ehash_locks_alloc() looks like this:

#ifdef CONFIG_NUMA
	if (size > PAGE_SIZE)
		x = vmalloc(...);
	else
#endif
		x = kmalloc(...);

Unlike it, the inet_ehash_locks_alloc() looks like this:

#ifdef CONFIG_NUMA
	if (size > PAGE_SIZE)
		vfree(x);
	else
#else
		kfree(x);
#endif

The error is obvious - if the NUMA is on and the size
is less than the PAGE_SIZE we leak the pointer (kfree is
inside the #else branch).

Compiler doesn't warn us because after the kfree(x) there's
a "x = NULL" assignment, so here's another (minor?) bug: we 
don't set x to NULL under certain circumstances.

Boring explanation, I know... Patch explains it better.

Signed-off-by: Pavel Emelyanov <xemul at openvz.org>

---

diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index 469216d..37f6cb1 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -186,9 +186,8 @@ static inline void inet_ehash_locks_free(struct inet_hashinfo *hashinfo)
 		if (size > PAGE_SIZE)
 			vfree(hashinfo->ehash_locks);
 		else
-#else
-		kfree(hashinfo->ehash_locks);
 #endif
+		kfree(hashinfo->ehash_locks);
 		hashinfo->ehash_locks = NULL;
 	}
 }




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