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From: Pavel Emelyanov <xemul@openvz.org>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Linux Netdev List <netdev@vger.kernel.org>, devel@openvz.org
Subject: [PATCH] Fix memory leak in inet_hashtables.h when NUMA is on
Date: Fri, 23 Nov 2007 19:13:11 +0300	[thread overview]
Message-ID: <4746FC17.9010300@openvz.org> (raw)

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@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;
 	}
 }

             reply	other threads:[~2007-11-23 16:13 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-11-23 16:13 Pavel Emelyanov [this message]
2007-11-26 12:36 ` [PATCH] Fix memory leak in inet_hashtables.h when NUMA is on Herbert Xu

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