[PATCH] ecryptfs: replace BUG_ON with error handling code

[PATCH] ecryptfs: replace BUG_ON with error handling code

[Aditya Pakki]

In crypt_scatterlist, if the crypt_stat argument is not set up
correctly, we avoid crashing, by returning the error upstream.
This patch performs the fix.

Signed-off-by: Aditya Pakki <pakki001@umn.edu>
---
 fs/ecryptfs/crypto.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index f91db24bbf3b..a064b408d841 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -311,8 +311,10 @@ static int crypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat,
 	struct extent_crypt_result ecr;
 	int rc = 0;
 
-	BUG_ON(!crypt_stat || !crypt_stat->tfm
-	       || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED));
+	if (!crypt_stat || !crypt_stat->tfm
+	       || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
+		return -EINVAL;
+
 	if (unlikely(ecryptfs_verbosity > 0)) {
 		ecryptfs_printk(KERN_DEBUG, "Key size [%zd]; key:\n",
 				crypt_stat->key_size);
-- 
2.20.1

Re: [PATCH] ecryptfs: replace BUG_ON with error handling code

[Markus Elfring]

> In crypt_scatterlist, if the crypt_stat argument is not set up
> correctly, we avoid crashing, by returning the error upstream.

Can an other change description be more helpful here?


> This patch performs the fix.

Please replace this sentence by the tag “Fixes”.

Regards,
Markus

Re: [PATCH] ecryptfs: replace BUG_ON with error handling code

[Tyler Hicks]

On 2019-12-15 11:24:04, Aditya Pakki wrote:
> In crypt_scatterlist, if the crypt_stat argument is not set up
> correctly, we avoid crashing, by returning the error upstream.
> This patch performs the fix.
> 
> Signed-off-by: Aditya Pakki <pakki001@umn.edu>

Hi Aditya - I wanted to check in to see if you are able to submit a new
revision taking into account the feedback from Markus.

Also, I'm curious if you've been able to hit this BUG_ON() or if you are
just being proactive in cleaning up this function?

Let me know if I can help you prepare a v2 of this patch. Thanks!

Tyler

> ---
>  fs/ecryptfs/crypto.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
> index f91db24bbf3b..a064b408d841 100644
> --- a/fs/ecryptfs/crypto.c
> +++ b/fs/ecryptfs/crypto.c
> @@ -311,8 +311,10 @@ static int crypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat,
>  	struct extent_crypt_result ecr;
>  	int rc = 0;
>  
> -	BUG_ON(!crypt_stat || !crypt_stat->tfm
> -	       || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED));
> +	if (!crypt_stat || !crypt_stat->tfm
> +	       || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
> +		return -EINVAL;
> +
>  	if (unlikely(ecryptfs_verbosity > 0)) {
>  		ecryptfs_printk(KERN_DEBUG, "Key size [%zd]; key:\n",
>  				crypt_stat->key_size);
> -- 
> 2.20.1
> 

Re: [PATCH] ecryptfs: replace BUG_ON with error handling code

[Aditya Pakki]

On 2/14/20 11:38 AM, Tyler Hicks wrote:
> On 2019-12-15 11:24:04, Aditya Pakki wrote:
>> In crypt_scatterlist, if the crypt_stat argument is not set up
>> correctly, we avoid crashing, by returning the error upstream.
>> This patch performs the fix.
>>
>> Signed-off-by: Aditya Pakki <pakki001@umn.edu>
> 
> Hi Aditya - I wanted to check in to see if you are able to submit a new
> revision taking into account the feedback from Markus.
> 
> Also, I'm curious if you've been able to hit this BUG_ON() or if you are
> just being proactive in cleaning up this function?
> 
> Let me know if I can help you prepare a v2 of this patch. Thanks!
> 
> Tyler
> 
>> ---
>>  fs/ecryptfs/crypto.c | 6 ++++--
>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
>> index f91db24bbf3b..a064b408d841 100644
>> --- a/fs/ecryptfs/crypto.c
>> +++ b/fs/ecryptfs/crypto.c
>> @@ -311,8 +311,10 @@ static int crypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat,
>>  	struct extent_crypt_result ecr;
>>  	int rc = 0;
>>  
>> -	BUG_ON(!crypt_stat || !crypt_stat->tfm
>> -	       || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED));
>> +	if (!crypt_stat || !crypt_stat->tfm
>> +	       || !(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
>> +		return -EINVAL;
>> +
>>  	if (unlikely(ecryptfs_verbosity > 0)) {
>>  		ecryptfs_printk(KERN_DEBUG, "Key size [%zd]; key:\n",
>>  				crypt_stat->key_size);
>> -- 
>> 2.20.1
>>

The bug was detected by a static analysis tool and have not encountered it. I can send a v2 right away.