2016-01-29 13:10:09

by Jerome Marchand

[permalink] [raw]
Subject: [PATCH] fix out of bound read in __test_aead()

__test_aead() reads MAX_IVLEN bytes from template[i].iv, but the
actual length of the initialisation vector can be shorter.
The length of the IV is already calculated earlier in the
function. Let's just reuses that.
This fix an out-of-bound error detected by KASan.

Signed-off-by: Jerome Marchand <[email protected]>
---
crypto/testmgr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index ae8c57fd..d3587d5 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -617,7 +617,7 @@ static int __test_aead(struct crypto_aead *tfm, int enc,
j++;

if (template[i].iv)
- memcpy(iv, template[i].iv, MAX_IVLEN);
+ memcpy(iv, template[i].iv, iv_len);
else
memset(iv, 0, MAX_IVLEN);

--
2.5.0


2016-02-01 14:26:46

by Herbert Xu

[permalink] [raw]
Subject: Re: [PATCH] fix out of bound read in __test_aead()

On Fri, Jan 29, 2016 at 02:10:09PM +0100, Jerome Marchand wrote:
> __test_aead() reads MAX_IVLEN bytes from template[i].iv, but the
> actual length of the initialisation vector can be shorter.
> The length of the IV is already calculated earlier in the
> function. Let's just reuses that.
> This fix an out-of-bound error detected by KASan.
>
> Signed-off-by: Jerome Marchand <[email protected]>

This patch creates a new warning that iv_len may be uninitialised.

Please fix this and resubmit.

Thanks,
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

2016-02-01 15:40:33

by Jerome Marchand

[permalink] [raw]
Subject: Re: [PATCH] fix out of bound read in __test_aead()

On 02/01/2016 03:26 PM, Herbert Xu wrote:
> On Fri, Jan 29, 2016 at 02:10:09PM +0100, Jerome Marchand wrote:
>> __test_aead() reads MAX_IVLEN bytes from template[i].iv, but the
>> actual length of the initialisation vector can be shorter.
>> The length of the IV is already calculated earlier in the
>> function. Let's just reuses that.
>> This fix an out-of-bound error detected by KASan.
>>
>> Signed-off-by: Jerome Marchand <[email protected]>
>
> This patch creates a new warning that iv_len may be uninitialised.

I see. iv_len is set for each templates. I don't see why we would like
to call crypto_aead_ivsize() more than once. Moving the initialization
of iv_len out of the loop should solve the warning.

>
> Please fix this and resubmit.

Will do.

Jerome

>
> Thanks,
>


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2016-02-03 12:58:21

by Jerome Marchand

[permalink] [raw]
Subject: [PATCH v2] fix out of bound read in __test_aead()

__test_aead() reads MAX_IVLEN bytes from template[i].iv, but the
actual length of the initialisation vector can be shorter.
The length of the IV is already calculated earlier in the
function. Let's just reuses that. Also the IV length is currently
calculated several time for no reason. Let's fix that too.
This fix an out-of-bound error detected by KASan.

Signed-off-by: Jerome Marchand <[email protected]>
---
crypto/testmgr.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index ae8c57fd..6691756 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -488,6 +488,8 @@ static int __test_aead(struct crypto_aead *tfm, int enc,
aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
tcrypt_complete, &result);

+ iv_len = crypto_aead_ivsize(tfm);
+
for (i = 0, j = 0; i < tcount; i++) {
if (template[i].np)
continue;
@@ -508,7 +510,6 @@ static int __test_aead(struct crypto_aead *tfm, int enc,

memcpy(input, template[i].input, template[i].ilen);
memcpy(assoc, template[i].assoc, template[i].alen);
- iv_len = crypto_aead_ivsize(tfm);
if (template[i].iv)
memcpy(iv, template[i].iv, iv_len);
else
@@ -617,7 +618,7 @@ static int __test_aead(struct crypto_aead *tfm, int enc,
j++;

if (template[i].iv)
- memcpy(iv, template[i].iv, MAX_IVLEN);
+ memcpy(iv, template[i].iv, iv_len);
else
memset(iv, 0, MAX_IVLEN);

--
2.5.0

2016-02-06 07:48:14

by Herbert Xu

[permalink] [raw]
Subject: Re: [PATCH v2] fix out of bound read in __test_aead()

On Wed, Feb 03, 2016 at 01:58:12PM +0100, Jerome Marchand wrote:
> __test_aead() reads MAX_IVLEN bytes from template[i].iv, but the
> actual length of the initialisation vector can be shorter.
> The length of the IV is already calculated earlier in the
> function. Let's just reuses that. Also the IV length is currently
> calculated several time for no reason. Let's fix that too.
> This fix an out-of-bound error detected by KASan.
>
> Signed-off-by: Jerome Marchand <[email protected]>

Applied.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt