RE: [PATCH](updated) rfc4106, Intel, AES-NI: Don't leak memory in rfc4106_set_hash_subkey()..

[Jesper Juhl <jj@chaosbits.net>]

On Fri, 11 Feb 2011, Jesper Juhl wrote:

> On Fri, 11 Feb 2011, Jesper Juhl wrote:
> 
> > On Fri, 11 Feb 2011, Paoloni, Gabriele wrote:
> > 
> > > Well anyway I think that the return value of "ablkcipher_request_alloc(ctr_tfm, GFP_KERNEL)" has to be changed from -EINVAL to -ENOMEM in case of failure. That is why would stay on the patch that Tadeusz proposed. Otherwise Juhl should send another one....
> > > 
> > I'll take a look again later this evening when I get home from work.
> > 
> Hopefully this takes care of all complaints and can actually get merged so 
> we can get the leak fixed (patch is against current cryptodev-2.6 tree).
> 
> 
> Fix up previous patch that failed to properly fix mem leak in 
> rfc4106_set_hash_subkey(). This add-on patch; fixes the leak. moves 
> kfree() out of the error path, returns -ENOMEM rather than -EINVAL when 
> ablkcipher_request_alloc() fails.
> 

And of course I just had to screw up and send the wrong diff. The one I 
sent does not compile and was a temporary file I imported into the mail by 
accident :-(
Below is the real patch - changelog above still applies - sorry about 
that.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
---
 aesni-intel_glue.c |   15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index e013552..e0e6340 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -874,19 +874,17 @@ rfc4106_set_hash_subkey(u8 *hash_subkey, const u8 *key, unsigned int key_len)
 
 	ret = crypto_ablkcipher_setkey(ctr_tfm, key, key_len);
 	if (ret)
-		goto out;
+		goto out_free_ablkcipher;
 
+	ret = -ENOMEM;
 	req = ablkcipher_request_alloc(ctr_tfm, GFP_KERNEL);
-	if (!req) {
-		ret = -EINVAL;
+	if (!req)
 		goto out_free_ablkcipher;
-	}
 
 	req_data = kmalloc(sizeof(*req_data), GFP_KERNEL);
-	if (!req_data) {
-		ret = -ENOMEM;
+	if (!req_data)
 		goto out_free_request;
-	}
+
 	memset(req_data->iv, 0, sizeof(req_data->iv));
 
 	/* Clear the data in the hash sub key container to zero.*/
@@ -911,12 +909,11 @@ rfc4106_set_hash_subkey(u8 *hash_subkey, const u8 *key, unsigned int key_len)
 		if (!ret)
 			ret = req_data->result.err;
 	}
+	kfree(req_data);
 out_free_request:
 	ablkcipher_request_free(req);
-	kfree(req_data);
 out_free_ablkcipher:
 	crypto_free_ablkcipher(ctr_tfm);
-out:
 	return ret;
 }
 
 
-- 
Jesper Juhl <jj@chaosbits.net>            http://www.chaosbits.net/
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