2015-07-08 19:44:13

by Laurent Navet

Subject: [PATCH] ext4 crypto: remove unneeded assignation

Return value of ext4_derive_key_aes() is stored but never used before
being overwritten.
Also fix coverity CID 1309760.

Signed-off-by: Laurent Navet <[email protected]>
---
fs/ext4/crypto_key.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c
index 442d24e..92f9172 100644
--- a/fs/ext4/crypto_key.c
+++ b/fs/ext4/crypto_key.c
@@ -218,7 +218,7 @@ retry:
BUILD_BUG_ON(EXT4_AES_128_ECB_KEY_SIZE !=
EXT4_KEY_DERIVATION_NONCE_SIZE);
BUG_ON(master_key->size != EXT4_AES_256_XTS_KEY_SIZE);
- res = ext4_derive_key_aes(ctx.nonce, master_key->raw,
+ ext4_derive_key_aes(ctx.nonce, master_key->raw,
raw_key);
got_key:
ctfm = crypto_alloc_ablkcipher(cipher_str, 0, 0);
--
2.1.4

2015-07-08 19:55:50

by Joe Perches

Subject: Re: [PATCH] ext4 crypto: remove unneeded assignation

On Wed, 2015-07-08 at 21:51 +0200, Laurent Navet wrote:
> Return value of ext4_derive_key_aes() is stored but never used before
> being overwritten.
> Also fix coverity CID 1309760.
>
> Signed-off-by: Laurent Navet <[email protected]>
> ---
> fs/ext4/crypto_key.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c
> index 442d24e..92f9172 100644
> --- a/fs/ext4/crypto_key.c
> +++ b/fs/ext4/crypto_key.c
> @@ -218,7 +218,7 @@ retry:
> BUILD_BUG_ON(EXT4_AES_128_ECB_KEY_SIZE !=
> EXT4_KEY_DERIVATION_NONCE_SIZE);
> BUG_ON(master_key->size != EXT4_AES_256_XTS_KEY_SIZE);
> - res = ext4_derive_key_aes(ctx.nonce, master_key->raw,
> + ext4_derive_key_aes(ctx.nonce, master_key->raw,
> raw_key);

More likely this should be:

res = ext4_derive_key_aes(,,,);
if (res)
goto out;

> got_key:
> ctfm = crypto_alloc_ablkcipher(cipher_str, 0, 0);

2015-07-08 20:01:21

by Darrick J. Wong

Subject: Re: [PATCH] ext4 crypto: remove unneeded assignation

On Wed, Jul 08, 2015 at 09:51:15PM +0200, Laurent Navet wrote:
> Return value of ext4_derive_key_aes() is stored but never used before
> being overwritten.
> Also fix coverity CID 1309760.
>
> Signed-off-by: Laurent Navet <[email protected]>
> ---
> fs/ext4/crypto_key.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c
> index 442d24e..92f9172 100644
> --- a/fs/ext4/crypto_key.c
> +++ b/fs/ext4/crypto_key.c
> @@ -218,7 +218,7 @@ retry:
> BUILD_BUG_ON(EXT4_AES_128_ECB_KEY_SIZE !=
> EXT4_KEY_DERIVATION_NONCE_SIZE);
> BUG_ON(master_key->size != EXT4_AES_256_XTS_KEY_SIZE);
> - res = ext4_derive_key_aes(ctx.nonce, master_key->raw,
> + ext4_derive_key_aes(ctx.nonce, master_key->raw,
> raw_key);

I don't think it's a good idea to drop the error code on the floor and keep
going as if nothing bad had happened.

--D

> got_key:
> ctfm = crypto_alloc_ablkcipher(cipher_str, 0, 0);
> --
> 2.1.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

2015-07-09 19:05:00

by Laurent Navet

Subject: Re: [PATCH] ext4 crypto: remove unneeded assignation

Make sense,
I send a v2, thank's

2015-07-08 22:01 UTC+02:00, Darrick J. Wong <[email protected]>:
> On Wed, Jul 08, 2015 at 09:51:15PM +0200, Laurent Navet wrote:
>> Return value of ext4_derive_key_aes() is stored but never used before
>> being overwritten.
>> Also fix coverity CID 1309760.
>>
>> Signed-off-by: Laurent Navet <[email protected]>
>> ---
>> fs/ext4/crypto_key.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c
>> index 442d24e..92f9172 100644
>> --- a/fs/ext4/crypto_key.c
>> +++ b/fs/ext4/crypto_key.c
>> @@ -218,7 +218,7 @@ retry:
>> BUILD_BUG_ON(EXT4_AES_128_ECB_KEY_SIZE !=
>> EXT4_KEY_DERIVATION_NONCE_SIZE);
>> BUG_ON(master_key->size != EXT4_AES_256_XTS_KEY_SIZE);
>> - res = ext4_derive_key_aes(ctx.nonce, master_key->raw,
>> + ext4_derive_key_aes(ctx.nonce, master_key->raw,
>> raw_key);
>
> I don't think it's a good idea to drop the error code on the floor and keep
> going as if nothing bad had happened.
>
> --D
>
>> got_key:
>> ctfm = crypto_alloc_ablkcipher(cipher_str, 0, 0);
>> --
>> 2.1.4
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
>> the body of a message to [email protected]
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>


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