Re: [PATCH v12 03/26] ima: Define ima_namespace struct and start moving variables into it

[Stefan Berger <stefanb@linux.ibm.com>]

On 5/20/22 22:33, Serge E. Hallyn wrote:

>> diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c
>> index 93056c03bf5a..e366a21dd8be 100644
>> --- a/security/integrity/ima/ima_queue_keys.c
>> +++ b/security/integrity/ima/ima_queue_keys.c
>> @@ -10,6 +10,7 @@
>>   
>>   #include <linux/user_namespace.h>
>>   #include <linux/workqueue.h>
>> +#include <linux/ima.h>
>>   #include <keys/asymmetric-type.h>
>>   #include "ima.h"
>>   
>> @@ -42,7 +43,7 @@ static bool timer_expired;
>>   static void ima_keys_handler(struct work_struct *work)
>>   {
>>   	timer_expired = true;
>> -	ima_process_queued_keys();
>> +	ima_process_queued_keys(&init_ima_ns);
>>   }
>>   
>>   /*
>> @@ -130,11 +131,15 @@ bool ima_queue_key(struct key *keyring, const void *payload,
>>    * This function sets ima_process_keys to true and processes queued keys.
>>    * From here on keys will be processed right away (not queued).
>>    */
>> -void ima_process_queued_keys(void)
>> +void ima_process_queued_keys(struct ima_namespace *ns)
>>   {
>>   	struct ima_key_entry *entry, *tmp;
>>   	bool process = false;
>>   
>> +	/* only applies to init_ima_ns */
> 
> Hm, yes, it seems to, but it should be unreachable with
> ns != &init_ima_ns, ever, right?
> 
> So it seems better to either not have this hunk at all, (both
> here and at ima_keys_handler()) or to actually have a BUG_ON.
> 
> Or am I completely misreading the situation?

No, you are right. This function is only calledwith ns = &init_ima_ns at 
the moment. How about changing it to this here?

if (WARN_ON(ns != &init_ima_ns))
         return;



> 
>> +	if (ns != &init_ima_ns)
>> +		return;
>> +
>>   	if (ima_process_keys)
>>   		return;
>>   
>> @@ -159,7 +164,7 @@ void ima_process_queued_keys(void)
>>   
>>   	list_for_each_entry_safe(entry, tmp, &ima_keys, list) {
>>   		if (!timer_expired)
>> -			process_buffer_measurement(&init_user_ns, NULL,
>> +			process_buffer_measurement(ns, &init_user_ns, NULL,
>>   						   entry->payload,
>>   						   entry->payload_len,
>>   						   entry->keyring_name,
>> -- 
>> 2.34.1