diff mbox series

[v7,05/18] landlock: refactor helper functions

Message ID 20220829170401.834298-6-konstantin.meskhidze@huawei.com (mailing list archive)
State Handled Elsewhere
Headers show
Series Network support for Landlock | expand

Commit Message

Konstantin Meskhidze (A) Aug. 29, 2022, 5:03 p.m. UTC 
Adds new key_type argument to init_layer_masks() helper functions.
This modification supports implementing new rule types in the next
Landlock versions.

Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
---

Changes since v6:
* Removes masks_size attribute from init_layer_masks().
* Refactors init_layer_masks() with new landlock_key_type.

Changes since v5:
* Splits commit.
* Formats code with clang-format-14.

Changes since v4:
* Refactors init_layer_masks(), get_handled_accesses()
and unmask_layers() functions to support multiple rule types.
* Refactors landlock_get_fs_access_mask() function with
LANDLOCK_MASK_ACCESS_FS mask.

Changes since v3:
* Splits commit.
* Refactors landlock_unmask_layers functions.

---
 security/landlock/fs.c      | 33 +++++++++++++++++-----------
 security/landlock/ruleset.c | 44 +++++++++++++++++++++++++++----------
 security/landlock/ruleset.h | 11 +++++-----
 3 files changed, 58 insertions(+), 30 deletions(-)

--
2.25.1

Comments

Mickaël Salaün Sept. 6, 2022, 8:07 a.m. UTC | #1 
You can improve the subject with: "landlock: Refactor unmask_layers() 
and init_layer_masks()"

On 29/08/2022 19:03, Konstantin Meskhidze wrote:
> Adds new key_type argument to init_layer_masks() helper functions.
> This modification supports implementing new rule types in the next
> Landlock versions.
> 
> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>

As for patch 2/18, you can append:
Co-developed-by: Mickaël Salaün <mic@digikod.net>


> ---
> 
> Changes since v6:
> * Removes masks_size attribute from init_layer_masks().
> * Refactors init_layer_masks() with new landlock_key_type.
> 
> Changes since v5:
> * Splits commit.
> * Formats code with clang-format-14.
> 
> Changes since v4:
> * Refactors init_layer_masks(), get_handled_accesses()
> and unmask_layers() functions to support multiple rule types.
> * Refactors landlock_get_fs_access_mask() function with
> LANDLOCK_MASK_ACCESS_FS mask.
> 
> Changes since v3:
> * Splits commit.
> * Refactors landlock_unmask_layers functions.
> 
> ---
>   security/landlock/fs.c      | 33 +++++++++++++++++-----------
>   security/landlock/ruleset.c | 44 +++++++++++++++++++++++++++----------
>   security/landlock/ruleset.h | 11 +++++-----
>   3 files changed, 58 insertions(+), 30 deletions(-)
> 
> diff --git a/security/landlock/fs.c b/security/landlock/fs.c
> index b03d6153f628..a4d9aea539cd 100644
> --- a/security/landlock/fs.c
> +++ b/security/landlock/fs.c
> @@ -439,16 +439,20 @@ static int check_access_path_dual(
>   	if (unlikely(dentry_child1)) {
>   		unmask_layers(find_rule(domain, dentry_child1),
>   			      init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS,
> -					       &_layer_masks_child1),
> -			      &_layer_masks_child1);
> +					       &_layer_masks_child1,
> +					       LANDLOCK_KEY_INODE),
> +			      &_layer_masks_child1,
> +			      ARRAY_SIZE(_layer_masks_child1));
>   		layer_masks_child1 = &_layer_masks_child1;
>   		child1_is_directory = d_is_dir(dentry_child1);
>   	}
>   	if (unlikely(dentry_child2)) {
>   		unmask_layers(find_rule(domain, dentry_child2),
>   			      init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS,
> -					       &_layer_masks_child2),
> -			      &_layer_masks_child2);
> +					       &_layer_masks_child2,
> +					       LANDLOCK_KEY_INODE),
> +			      &_layer_masks_child2,
> +			      ARRAY_SIZE(_layer_masks_child2));
>   		layer_masks_child2 = &_layer_masks_child2;
>   		child2_is_directory = d_is_dir(dentry_child2);
>   	}
> @@ -500,15 +504,16 @@ static int check_access_path_dual(
>   		}
> 
>   		rule = find_rule(domain, walker_path.dentry);
> -		allowed_parent1 = unmask_layers(rule, access_masked_parent1,
> -						layer_masks_parent1);
> -		allowed_parent2 = unmask_layers(rule, access_masked_parent2,
> -						layer_masks_parent2);
> +		allowed_parent1 = unmask_layers(
> +			rule, access_masked_parent1, layer_masks_parent1,
> +			ARRAY_SIZE(*layer_masks_parent1));
> +		allowed_parent2 = unmask_layers(
> +			rule, access_masked_parent2, layer_masks_parent2,
> +			ARRAY_SIZE(*layer_masks_parent2));
> 
>   		/* Stops when a rule from each layer grants access. */
>   		if (allowed_parent1 && allowed_parent2)
>   			break;
> -
>   jump_up:
>   		if (walker_path.dentry == walker_path.mnt->mnt_root) {
>   			if (follow_up(&walker_path)) {
> @@ -564,7 +569,8 @@ static inline int check_access_path(const struct landlock_ruleset *const domain,
>   {
>   	layer_mask_t layer_masks[LANDLOCK_NUM_ACCESS_FS] = {};
> 
> -	access_request = init_layer_masks(domain, access_request, &layer_masks);
> +	access_request = init_layer_masks(domain, access_request, &layer_masks,
> +					  LANDLOCK_KEY_INODE);
>   	return check_access_path_dual(domain, path, access_request,
>   				      &layer_masks, NULL, 0, NULL, NULL);
>   }
> @@ -648,7 +654,7 @@ static bool collect_domain_accesses(
>   		return true;
> 
>   	access_dom = init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS,
> -				      layer_masks_dom);
> +				      layer_masks_dom, LANDLOCK_KEY_INODE);
> 
>   	dget(dir);
>   	while (true) {
> @@ -656,7 +662,8 @@ static bool collect_domain_accesses(
> 
>   		/* Gets all layers allowing all domain accesses. */
>   		if (unmask_layers(find_rule(domain, dir), access_dom,
> -				  layer_masks_dom)) {
> +				  layer_masks_dom,
> +				  ARRAY_SIZE(*layer_masks_dom))) {
>   			/*
>   			 * Stops when all handled accesses are allowed by at
>   			 * least one rule in each layer.
> @@ -772,7 +779,7 @@ static int current_check_refer_path(struct dentry *const old_dentry,
>   		 */
>   		access_request_parent1 = init_layer_masks(
>   			dom, access_request_parent1 | access_request_parent2,
> -			&layer_masks_parent1);
> +			&layer_masks_parent1, LANDLOCK_KEY_INODE);
>   		return check_access_path_dual(dom, new_dir,
>   					      access_request_parent1,
>   					      &layer_masks_parent1, NULL, 0,
> diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c
> index 671a95e2a345..84fcd8eb30d4 100644
> --- a/security/landlock/ruleset.c
> +++ b/security/landlock/ruleset.c
> @@ -574,7 +574,8 @@ landlock_find_rule(const struct landlock_ruleset *const ruleset,
>    */

You missed another hunk from my patch… Please do a diff with it.


>   bool unmask_layers(const struct landlock_rule *const rule,
>   		   const access_mask_t access_request,
> -		   layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS])
> +		   layer_mask_t (*const layer_masks)[],
> +		   const size_t masks_array_size)
>   {
>   	size_t layer_level;
> 
> @@ -606,8 +607,7 @@ bool unmask_layers(const struct landlock_rule *const rule,
>   		 * requested access.
>   		 */
>   		is_empty = true;
> -		for_each_set_bit(access_bit, &access_req,
> -				 ARRAY_SIZE(*layer_masks)) {
> +		for_each_set_bit(access_bit, &access_req, masks_array_size) {
>   			if (layer->access & BIT_ULL(access_bit))
>   				(*layer_masks)[access_bit] &= ~layer_bit;
>   			is_empty = is_empty && !(*layer_masks)[access_bit];
> @@ -618,15 +618,36 @@ bool unmask_layers(const struct landlock_rule *const rule,
>   	return false;
>   }
> 
> -access_mask_t
> -init_layer_masks(const struct landlock_ruleset *const domain,
> -		 const access_mask_t access_request,
> -		 layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS])
> +typedef access_mask_t
> +get_access_mask_t(const struct landlock_ruleset *const ruleset,
> +		  const u16 layer_level);
> +
> +/*
> + * @layer_masks must contain LANDLOCK_NUM_ACCESS_FS or LANDLOCK_NUM_ACCESS_NET
> + * elements according to @key_type.
> + */
> +access_mask_t init_layer_masks(const struct landlock_ruleset *const domain,
> +			       const access_mask_t access_request,
> +			       layer_mask_t (*const layer_masks)[],
> +			       const enum landlock_key_type key_type)
>   {
>   	access_mask_t handled_accesses = 0;
> -	size_t layer_level;
> +	size_t layer_level, num_access;
> +	get_access_mask_t *get_access_mask;
> +
> +	switch (key_type) {
> +	case LANDLOCK_KEY_INODE:
> +		get_access_mask = landlock_get_fs_access_mask;
> +		num_access = LANDLOCK_NUM_ACCESS_FS;
> +		break;
> +	default:
> +		WARN_ON_ONCE(1);
> +		return 0;
> +	}
> +
> +	memset(layer_masks, 0,
> +	       array_size(sizeof((*layer_masks)[0]), num_access));
> 
> -	memset(layer_masks, 0, sizeof(*layer_masks));
>   	/* An empty access request can happen because of O_WRONLY | O_RDWR. */
>   	if (!access_request)
>   		return 0;
> @@ -636,9 +657,8 @@ init_layer_masks(const struct landlock_ruleset *const domain,
>   		const unsigned long access_req = access_request;
>   		unsigned long access_bit;
> 
> -		for_each_set_bit(access_bit, &access_req,
> -				 ARRAY_SIZE(*layer_masks)) {
> -			if (landlock_get_fs_access_mask(domain, layer_level) &
> +		for_each_set_bit(access_bit, &access_req, num_access) {
> +			if (get_access_mask(domain, layer_level) &
>   			    BIT_ULL(access_bit)) {
>   				(*layer_masks)[access_bit] |=
>   					BIT_ULL(layer_level);
> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h
> index d7d9b987829c..2083855bf42d 100644
> --- a/security/landlock/ruleset.h
> +++ b/security/landlock/ruleset.h
> @@ -238,11 +238,12 @@ landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset,
> 
>   bool unmask_layers(const struct landlock_rule *const rule,
>   		   const access_mask_t access_request,
> -		   layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]);
> +		   layer_mask_t (*const layer_masks)[],
> +		   const size_t masks_array_size);
> 
> -access_mask_t
> -init_layer_masks(const struct landlock_ruleset *const domain,
> -		 const access_mask_t access_request,
> -		 layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]);
> +access_mask_t init_layer_masks(const struct landlock_ruleset *const domain,
> +			       const access_mask_t access_request,
> +			       layer_mask_t (*const layer_masks)[],
> +			       const enum landlock_key_type key_type);
> 
>   #endif /* _SECURITY_LANDLOCK_RULESET_H */
> --
> 2.25.1
>
Konstantin Meskhidze (A) Sept. 10, 2022, 5:20 p.m. UTC | #2 
9/6/2022 11:07 AM, Mickaël Salaün пишет:
> You can improve the subject with: "landlock: Refactor unmask_layers()
> and init_layer_masks()"

   Got it. I will change it.
> 
> On 29/08/2022 19:03, Konstantin Meskhidze wrote:
>> Adds new key_type argument to init_layer_masks() helper functions.
>> This modification supports implementing new rule types in the next
>> Landlock versions.
>> 
>> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
> 
> As for patch 2/18, you can append:
> Co-developed-by: Mickaël Salaün <mic@digikod.net>

   Ok. I will append. Thanks.>
> 
>> ---
>> 
>> Changes since v6:
>> * Removes masks_size attribute from init_layer_masks().
>> * Refactors init_layer_masks() with new landlock_key_type.
>> 
>> Changes since v5:
>> * Splits commit.
>> * Formats code with clang-format-14.
>> 
>> Changes since v4:
>> * Refactors init_layer_masks(), get_handled_accesses()
>> and unmask_layers() functions to support multiple rule types.
>> * Refactors landlock_get_fs_access_mask() function with
>> LANDLOCK_MASK_ACCESS_FS mask.
>> 
>> Changes since v3:
>> * Splits commit.
>> * Refactors landlock_unmask_layers functions.
>> 
>> ---
>>   security/landlock/fs.c      | 33 +++++++++++++++++-----------
>>   security/landlock/ruleset.c | 44 +++++++++++++++++++++++++++----------
>>   security/landlock/ruleset.h | 11 +++++-----
>>   3 files changed, 58 insertions(+), 30 deletions(-)
>> 
>> diff --git a/security/landlock/fs.c b/security/landlock/fs.c
>> index b03d6153f628..a4d9aea539cd 100644
>> --- a/security/landlock/fs.c
>> +++ b/security/landlock/fs.c
>> @@ -439,16 +439,20 @@ static int check_access_path_dual(
>>   	if (unlikely(dentry_child1)) {
>>   		unmask_layers(find_rule(domain, dentry_child1),
>>   			      init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS,
>> -					       &_layer_masks_child1),
>> -			      &_layer_masks_child1);
>> +					       &_layer_masks_child1,
>> +					       LANDLOCK_KEY_INODE),
>> +			      &_layer_masks_child1,
>> +			      ARRAY_SIZE(_layer_masks_child1));
>>   		layer_masks_child1 = &_layer_masks_child1;
>>   		child1_is_directory = d_is_dir(dentry_child1);
>>   	}
>>   	if (unlikely(dentry_child2)) {
>>   		unmask_layers(find_rule(domain, dentry_child2),
>>   			      init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS,
>> -					       &_layer_masks_child2),
>> -			      &_layer_masks_child2);
>> +					       &_layer_masks_child2,
>> +					       LANDLOCK_KEY_INODE),
>> +			      &_layer_masks_child2,
>> +			      ARRAY_SIZE(_layer_masks_child2));
>>   		layer_masks_child2 = &_layer_masks_child2;
>>   		child2_is_directory = d_is_dir(dentry_child2);
>>   	}
>> @@ -500,15 +504,16 @@ static int check_access_path_dual(
>>   		}
>> 
>>   		rule = find_rule(domain, walker_path.dentry);
>> -		allowed_parent1 = unmask_layers(rule, access_masked_parent1,
>> -						layer_masks_parent1);
>> -		allowed_parent2 = unmask_layers(rule, access_masked_parent2,
>> -						layer_masks_parent2);
>> +		allowed_parent1 = unmask_layers(
>> +			rule, access_masked_parent1, layer_masks_parent1,
>> +			ARRAY_SIZE(*layer_masks_parent1));
>> +		allowed_parent2 = unmask_layers(
>> +			rule, access_masked_parent2, layer_masks_parent2,
>> +			ARRAY_SIZE(*layer_masks_parent2));
>> 
>>   		/* Stops when a rule from each layer grants access. */
>>   		if (allowed_parent1 && allowed_parent2)
>>   			break;
>> -
>>   jump_up:
>>   		if (walker_path.dentry == walker_path.mnt->mnt_root) {
>>   			if (follow_up(&walker_path)) {
>> @@ -564,7 +569,8 @@ static inline int check_access_path(const struct landlock_ruleset *const domain,
>>   {
>>   	layer_mask_t layer_masks[LANDLOCK_NUM_ACCESS_FS] = {};
>> 
>> -	access_request = init_layer_masks(domain, access_request, &layer_masks);
>> +	access_request = init_layer_masks(domain, access_request, &layer_masks,
>> +					  LANDLOCK_KEY_INODE);
>>   	return check_access_path_dual(domain, path, access_request,
>>   				      &layer_masks, NULL, 0, NULL, NULL);
>>   }
>> @@ -648,7 +654,7 @@ static bool collect_domain_accesses(
>>   		return true;
>> 
>>   	access_dom = init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS,
>> -				      layer_masks_dom);
>> +				      layer_masks_dom, LANDLOCK_KEY_INODE);
>> 
>>   	dget(dir);
>>   	while (true) {
>> @@ -656,7 +662,8 @@ static bool collect_domain_accesses(
>> 
>>   		/* Gets all layers allowing all domain accesses. */
>>   		if (unmask_layers(find_rule(domain, dir), access_dom,
>> -				  layer_masks_dom)) {
>> +				  layer_masks_dom,
>> +				  ARRAY_SIZE(*layer_masks_dom))) {
>>   			/*
>>   			 * Stops when all handled accesses are allowed by at
>>   			 * least one rule in each layer.
>> @@ -772,7 +779,7 @@ static int current_check_refer_path(struct dentry *const old_dentry,
>>   		 */
>>   		access_request_parent1 = init_layer_masks(
>>   			dom, access_request_parent1 | access_request_parent2,
>> -			&layer_masks_parent1);
>> +			&layer_masks_parent1, LANDLOCK_KEY_INODE);
>>   		return check_access_path_dual(dom, new_dir,
>>   					      access_request_parent1,
>>   					      &layer_masks_parent1, NULL, 0,
>> diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c
>> index 671a95e2a345..84fcd8eb30d4 100644
>> --- a/security/landlock/ruleset.c
>> +++ b/security/landlock/ruleset.c
>> @@ -574,7 +574,8 @@ landlock_find_rule(const struct landlock_ruleset *const ruleset,
>>    */
> 
> You missed another hunk from my patch… Please do a diff with it.

   Sorry. What did I miss here?
> 
> 
>>   bool unmask_layers(const struct landlock_rule *const rule,
>>   		   const access_mask_t access_request,
>> -		   layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS])
>> +		   layer_mask_t (*const layer_masks)[],
>> +		   const size_t masks_array_size)
>>   {
>>   	size_t layer_level;
>> 
>> @@ -606,8 +607,7 @@ bool unmask_layers(const struct landlock_rule *const rule,
>>   		 * requested access.
>>   		 */
>>   		is_empty = true;
>> -		for_each_set_bit(access_bit, &access_req,
>> -				 ARRAY_SIZE(*layer_masks)) {
>> +		for_each_set_bit(access_bit, &access_req, masks_array_size) {
>>   			if (layer->access & BIT_ULL(access_bit))
>>   				(*layer_masks)[access_bit] &= ~layer_bit;
>>   			is_empty = is_empty && !(*layer_masks)[access_bit];
>> @@ -618,15 +618,36 @@ bool unmask_layers(const struct landlock_rule *const rule,
>>   	return false;
>>   }
>> 
>> -access_mask_t
>> -init_layer_masks(const struct landlock_ruleset *const domain,
>> -		 const access_mask_t access_request,
>> -		 layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS])
>> +typedef access_mask_t
>> +get_access_mask_t(const struct landlock_ruleset *const ruleset,
>> +		  const u16 layer_level);
>> +
>> +/*
>> + * @layer_masks must contain LANDLOCK_NUM_ACCESS_FS or LANDLOCK_NUM_ACCESS_NET
>> + * elements according to @key_type.
>> + */
>> +access_mask_t init_layer_masks(const struct landlock_ruleset *const domain,
>> +			       const access_mask_t access_request,
>> +			       layer_mask_t (*const layer_masks)[],
>> +			       const enum landlock_key_type key_type)
>>   {
>>   	access_mask_t handled_accesses = 0;
>> -	size_t layer_level;
>> +	size_t layer_level, num_access;
>> +	get_access_mask_t *get_access_mask;
>> +
>> +	switch (key_type) {
>> +	case LANDLOCK_KEY_INODE:
>> +		get_access_mask = landlock_get_fs_access_mask;
>> +		num_access = LANDLOCK_NUM_ACCESS_FS;
>> +		break;
>> +	default:
>> +		WARN_ON_ONCE(1);
>> +		return 0;
>> +	}
>> +
>> +	memset(layer_masks, 0,
>> +	       array_size(sizeof((*layer_masks)[0]), num_access));
>> 
>> -	memset(layer_masks, 0, sizeof(*layer_masks));
>>   	/* An empty access request can happen because of O_WRONLY | O_RDWR. */
>>   	if (!access_request)
>>   		return 0;
>> @@ -636,9 +657,8 @@ init_layer_masks(const struct landlock_ruleset *const domain,
>>   		const unsigned long access_req = access_request;
>>   		unsigned long access_bit;
>> 
>> -		for_each_set_bit(access_bit, &access_req,
>> -				 ARRAY_SIZE(*layer_masks)) {
>> -			if (landlock_get_fs_access_mask(domain, layer_level) &
>> +		for_each_set_bit(access_bit, &access_req, num_access) {
>> +			if (get_access_mask(domain, layer_level) &
>>   			    BIT_ULL(access_bit)) {
>>   				(*layer_masks)[access_bit] |=
>>   					BIT_ULL(layer_level);
>> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h
>> index d7d9b987829c..2083855bf42d 100644
>> --- a/security/landlock/ruleset.h
>> +++ b/security/landlock/ruleset.h
>> @@ -238,11 +238,12 @@ landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset,
>> 
>>   bool unmask_layers(const struct landlock_rule *const rule,
>>   		   const access_mask_t access_request,
>> -		   layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]);
>> +		   layer_mask_t (*const layer_masks)[],
>> +		   const size_t masks_array_size);
>> 
>> -access_mask_t
>> -init_layer_masks(const struct landlock_ruleset *const domain,
>> -		 const access_mask_t access_request,
>> -		 layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]);
>> +access_mask_t init_layer_masks(const struct landlock_ruleset *const domain,
>> +			       const access_mask_t access_request,
>> +			       layer_mask_t (*const layer_masks)[],
>> +			       const enum landlock_key_type key_type);
>> 
>>   #endif /* _SECURITY_LANDLOCK_RULESET_H */
>> --
>> 2.25.1
>> 
> .
Mickaël Salaün Sept. 12, 2022, 5:18 p.m. UTC | #3 
On 10/09/2022 19:20, Konstantin Meskhidze (A) wrote:
> 
> 
> 9/6/2022 11:07 AM, Mickaël Salaün пишет:

[...]

>>> diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c
>>> index 671a95e2a345..84fcd8eb30d4 100644
>>> --- a/security/landlock/ruleset.c
>>> +++ b/security/landlock/ruleset.c
>>> @@ -574,7 +574,8 @@ landlock_find_rule(const struct landlock_ruleset *const ruleset,
>>>     */
>>
>> You missed another hunk from my patch… Please do a diff with it.
> 
>     Sorry. What did I miss here?

There is at least missing comments, please do a diff with my (rebased) 
changes, you'll see.

I wrote all the changes in my commit messages, please include them in 
the related patches (at the correct version).


>>
>>
>>>    bool unmask_layers(const struct landlock_rule *const rule,
>>>    		   const access_mask_t access_request,
>>> -		   layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS])
>>> +		   layer_mask_t (*const layer_masks)[],
>>> +		   const size_t masks_array_size)
>>>    {
>>>    	size_t layer_level;
>>>
>>> @@ -606,8 +607,7 @@ bool unmask_layers(const struct landlock_rule *const rule,
>>>    		 * requested access.
>>>    		 */
>>>    		is_empty = true;
>>> -		for_each_set_bit(access_bit, &access_req,
>>> -				 ARRAY_SIZE(*layer_masks)) {
>>> +		for_each_set_bit(access_bit, &access_req, masks_array_size) {
>>>    			if (layer->access & BIT_ULL(access_bit))
>>>    				(*layer_masks)[access_bit] &= ~layer_bit;
>>>    			is_empty = is_empty && !(*layer_masks)[access_bit];
>>> @@ -618,15 +618,36 @@ bool unmask_layers(const struct landlock_rule *const rule,
>>>    	return false;
>>>    }
>>>
>>> -access_mask_t
>>> -init_layer_masks(const struct landlock_ruleset *const domain,
>>> -		 const access_mask_t access_request,
>>> -		 layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS])
>>> +typedef access_mask_t
>>> +get_access_mask_t(const struct landlock_ruleset *const ruleset,
>>> +		  const u16 layer_level);
>>> +
>>> +/*
>>> + * @layer_masks must contain LANDLOCK_NUM_ACCESS_FS or LANDLOCK_NUM_ACCESS_NET
>>> + * elements according to @key_type.
>>> + */
>>> +access_mask_t init_layer_masks(const struct landlock_ruleset *const domain,
>>> +			       const access_mask_t access_request,
>>> +			       layer_mask_t (*const layer_masks)[],
>>> +			       const enum landlock_key_type key_type)
>>>    {
>>>    	access_mask_t handled_accesses = 0;
>>> -	size_t layer_level;
>>> +	size_t layer_level, num_access;
>>> +	get_access_mask_t *get_access_mask;
>>> +
>>> +	switch (key_type) {
>>> +	case LANDLOCK_KEY_INODE:
>>> +		get_access_mask = landlock_get_fs_access_mask;
>>> +		num_access = LANDLOCK_NUM_ACCESS_FS;
>>> +		break;
>>> +	default:
>>> +		WARN_ON_ONCE(1);
>>> +		return 0;
>>> +	}
>>> +
>>> +	memset(layer_masks, 0,
>>> +	       array_size(sizeof((*layer_masks)[0]), num_access));
>>>
>>> -	memset(layer_masks, 0, sizeof(*layer_masks));
>>>    	/* An empty access request can happen because of O_WRONLY | O_RDWR. */
>>>    	if (!access_request)
>>>    		return 0;
>>> @@ -636,9 +657,8 @@ init_layer_masks(const struct landlock_ruleset *const domain,
>>>    		const unsigned long access_req = access_request;
>>>    		unsigned long access_bit;
>>>
>>> -		for_each_set_bit(access_bit, &access_req,
>>> -				 ARRAY_SIZE(*layer_masks)) {
>>> -			if (landlock_get_fs_access_mask(domain, layer_level) &
>>> +		for_each_set_bit(access_bit, &access_req, num_access) {
>>> +			if (get_access_mask(domain, layer_level) &
>>>    			    BIT_ULL(access_bit)) {
>>>    				(*layer_masks)[access_bit] |=
>>>    					BIT_ULL(layer_level);
>>> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h
>>> index d7d9b987829c..2083855bf42d 100644
>>> --- a/security/landlock/ruleset.h
>>> +++ b/security/landlock/ruleset.h
>>> @@ -238,11 +238,12 @@ landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset,
>>>
>>>    bool unmask_layers(const struct landlock_rule *const rule,
>>>    		   const access_mask_t access_request,
>>> -		   layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]);
>>> +		   layer_mask_t (*const layer_masks)[],
>>> +		   const size_t masks_array_size);
>>>
>>> -access_mask_t
>>> -init_layer_masks(const struct landlock_ruleset *const domain,
>>> -		 const access_mask_t access_request,
>>> -		 layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]);
>>> +access_mask_t init_layer_masks(const struct landlock_ruleset *const domain,
>>> +			       const access_mask_t access_request,
>>> +			       layer_mask_t (*const layer_masks)[],
>>> +			       const enum landlock_key_type key_type);
>>>
>>>    #endif /* _SECURITY_LANDLOCK_RULESET_H */
>>> --
>>> 2.25.1
>>>
>> .
diff mbox series

Patch

diff --git a/security/landlock/fs.c b/security/landlock/fs.c
index b03d6153f628..a4d9aea539cd 100644
--- a/security/landlock/fs.c
+++ b/security/landlock/fs.c
@@ -439,16 +439,20 @@  static int check_access_path_dual(
 	if (unlikely(dentry_child1)) {
 		unmask_layers(find_rule(domain, dentry_child1),
 			      init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS,
-					       &_layer_masks_child1),
-			      &_layer_masks_child1);
+					       &_layer_masks_child1,
+					       LANDLOCK_KEY_INODE),
+			      &_layer_masks_child1,
+			      ARRAY_SIZE(_layer_masks_child1));
 		layer_masks_child1 = &_layer_masks_child1;
 		child1_is_directory = d_is_dir(dentry_child1);
 	}
 	if (unlikely(dentry_child2)) {
 		unmask_layers(find_rule(domain, dentry_child2),
 			      init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS,
-					       &_layer_masks_child2),
-			      &_layer_masks_child2);
+					       &_layer_masks_child2,
+					       LANDLOCK_KEY_INODE),
+			      &_layer_masks_child2,
+			      ARRAY_SIZE(_layer_masks_child2));
 		layer_masks_child2 = &_layer_masks_child2;
 		child2_is_directory = d_is_dir(dentry_child2);
 	}
@@ -500,15 +504,16 @@  static int check_access_path_dual(
 		}

 		rule = find_rule(domain, walker_path.dentry);
-		allowed_parent1 = unmask_layers(rule, access_masked_parent1,
-						layer_masks_parent1);
-		allowed_parent2 = unmask_layers(rule, access_masked_parent2,
-						layer_masks_parent2);
+		allowed_parent1 = unmask_layers(
+			rule, access_masked_parent1, layer_masks_parent1,
+			ARRAY_SIZE(*layer_masks_parent1));
+		allowed_parent2 = unmask_layers(
+			rule, access_masked_parent2, layer_masks_parent2,
+			ARRAY_SIZE(*layer_masks_parent2));

 		/* Stops when a rule from each layer grants access. */
 		if (allowed_parent1 && allowed_parent2)
 			break;
-
 jump_up:
 		if (walker_path.dentry == walker_path.mnt->mnt_root) {
 			if (follow_up(&walker_path)) {
@@ -564,7 +569,8 @@  static inline int check_access_path(const struct landlock_ruleset *const domain,
 {
 	layer_mask_t layer_masks[LANDLOCK_NUM_ACCESS_FS] = {};

-	access_request = init_layer_masks(domain, access_request, &layer_masks);
+	access_request = init_layer_masks(domain, access_request, &layer_masks,
+					  LANDLOCK_KEY_INODE);
 	return check_access_path_dual(domain, path, access_request,
 				      &layer_masks, NULL, 0, NULL, NULL);
 }
@@ -648,7 +654,7 @@  static bool collect_domain_accesses(
 		return true;

 	access_dom = init_layer_masks(domain, LANDLOCK_MASK_ACCESS_FS,
-				      layer_masks_dom);
+				      layer_masks_dom, LANDLOCK_KEY_INODE);

 	dget(dir);
 	while (true) {
@@ -656,7 +662,8 @@  static bool collect_domain_accesses(

 		/* Gets all layers allowing all domain accesses. */
 		if (unmask_layers(find_rule(domain, dir), access_dom,
-				  layer_masks_dom)) {
+				  layer_masks_dom,
+				  ARRAY_SIZE(*layer_masks_dom))) {
 			/*
 			 * Stops when all handled accesses are allowed by at
 			 * least one rule in each layer.
@@ -772,7 +779,7 @@  static int current_check_refer_path(struct dentry *const old_dentry,
 		 */
 		access_request_parent1 = init_layer_masks(
 			dom, access_request_parent1 | access_request_parent2,
-			&layer_masks_parent1);
+			&layer_masks_parent1, LANDLOCK_KEY_INODE);
 		return check_access_path_dual(dom, new_dir,
 					      access_request_parent1,
 					      &layer_masks_parent1, NULL, 0,
diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c
index 671a95e2a345..84fcd8eb30d4 100644
--- a/security/landlock/ruleset.c
+++ b/security/landlock/ruleset.c
@@ -574,7 +574,8 @@  landlock_find_rule(const struct landlock_ruleset *const ruleset,
  */
 bool unmask_layers(const struct landlock_rule *const rule,
 		   const access_mask_t access_request,
-		   layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS])
+		   layer_mask_t (*const layer_masks)[],
+		   const size_t masks_array_size)
 {
 	size_t layer_level;

@@ -606,8 +607,7 @@  bool unmask_layers(const struct landlock_rule *const rule,
 		 * requested access.
 		 */
 		is_empty = true;
-		for_each_set_bit(access_bit, &access_req,
-				 ARRAY_SIZE(*layer_masks)) {
+		for_each_set_bit(access_bit, &access_req, masks_array_size) {
 			if (layer->access & BIT_ULL(access_bit))
 				(*layer_masks)[access_bit] &= ~layer_bit;
 			is_empty = is_empty && !(*layer_masks)[access_bit];
@@ -618,15 +618,36 @@  bool unmask_layers(const struct landlock_rule *const rule,
 	return false;
 }

-access_mask_t
-init_layer_masks(const struct landlock_ruleset *const domain,
-		 const access_mask_t access_request,
-		 layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS])
+typedef access_mask_t
+get_access_mask_t(const struct landlock_ruleset *const ruleset,
+		  const u16 layer_level);
+
+/*
+ * @layer_masks must contain LANDLOCK_NUM_ACCESS_FS or LANDLOCK_NUM_ACCESS_NET
+ * elements according to @key_type.
+ */
+access_mask_t init_layer_masks(const struct landlock_ruleset *const domain,
+			       const access_mask_t access_request,
+			       layer_mask_t (*const layer_masks)[],
+			       const enum landlock_key_type key_type)
 {
 	access_mask_t handled_accesses = 0;
-	size_t layer_level;
+	size_t layer_level, num_access;
+	get_access_mask_t *get_access_mask;
+
+	switch (key_type) {
+	case LANDLOCK_KEY_INODE:
+		get_access_mask = landlock_get_fs_access_mask;
+		num_access = LANDLOCK_NUM_ACCESS_FS;
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		return 0;
+	}
+
+	memset(layer_masks, 0,
+	       array_size(sizeof((*layer_masks)[0]), num_access));

-	memset(layer_masks, 0, sizeof(*layer_masks));
 	/* An empty access request can happen because of O_WRONLY | O_RDWR. */
 	if (!access_request)
 		return 0;
@@ -636,9 +657,8 @@  init_layer_masks(const struct landlock_ruleset *const domain,
 		const unsigned long access_req = access_request;
 		unsigned long access_bit;

-		for_each_set_bit(access_bit, &access_req,
-				 ARRAY_SIZE(*layer_masks)) {
-			if (landlock_get_fs_access_mask(domain, layer_level) &
+		for_each_set_bit(access_bit, &access_req, num_access) {
+			if (get_access_mask(domain, layer_level) &
 			    BIT_ULL(access_bit)) {
 				(*layer_masks)[access_bit] |=
 					BIT_ULL(layer_level);
diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h
index d7d9b987829c..2083855bf42d 100644
--- a/security/landlock/ruleset.h
+++ b/security/landlock/ruleset.h
@@ -238,11 +238,12 @@  landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset,

 bool unmask_layers(const struct landlock_rule *const rule,
 		   const access_mask_t access_request,
-		   layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]);
+		   layer_mask_t (*const layer_masks)[],
+		   const size_t masks_array_size);

-access_mask_t
-init_layer_masks(const struct landlock_ruleset *const domain,
-		 const access_mask_t access_request,
-		 layer_mask_t (*const layer_masks)[LANDLOCK_NUM_ACCESS_FS]);
+access_mask_t init_layer_masks(const struct landlock_ruleset *const domain,
+			       const access_mask_t access_request,
+			       layer_mask_t (*const layer_masks)[],
+			       const enum landlock_key_type key_type);

 #endif /* _SECURITY_LANDLOCK_RULESET_H */