3/22/2022 4:24 PM, Mickaël Salaün пишет:
On 22/03/2022 13:33, Konstantin Meskhidze wrote:
3/18/2022 9:33 PM, Mickaël Salaün пишет:
On 17/03/2022 15:29, Konstantin Meskhidze wrote:
3/16/2022 11:27 AM, Mickaël Salaün пишет:
On 09/03/2022 14:44, Konstantin Meskhidze wrote:
A new object union added to support a socket port
rule type. To support it landlock_insert_rule() and
landlock_find_rule() were refactored. Now adding
or searching a rule in a ruleset depends on a
rule_type argument provided in refactored
functions mentioned above.
Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@xxxxxxxxxx>
---
[...]
@@ -156,26 +166,38 @@ static void build_check_ruleset(void)
* access rights.
*/
static int insert_rule(struct landlock_ruleset *const ruleset,
- struct landlock_object *const object,
+ struct landlock_object *const object_ptr,
+ const uintptr_t object_data,
Can you move rule_type here for this function and similar ones? It
makes sense to group object-related arguments.
Just to group them together, not putting rule_type in the end?
Yes
Ok. Got it.
[...]
@@ -465,20 +501,28 @@ struct landlock_ruleset
*landlock_merge_ruleset(
*/
const struct landlock_rule *landlock_find_rule(
const struct landlock_ruleset *const ruleset,
- const struct landlock_object *const object)
+ const uintptr_t object_data, const u16 rule_type)
{
const struct rb_node *node;
- if (!object)
+ if (!object_data)
object_data can be 0. You need to add a test with such value.
We need to be sure that this change cannot affect the current FS code.
I got it. I will refactor it.
Well, 0 means a port 0, which might not be correct, but this check
should not be performed by landlock_merge_ruleset().
Do you mean landlock_find_rule()?? Cause this check is not
performed in landlock_merge_ruleset().
Yes, I was thinking about landlock_find_rule(). If you run your tests
with the patch I proposed, you'll see that one of these tests will fail
(when port equal 0). When creating a new network rule,
add_rule_net_service() should check if the port value is valid. However,
the above `if (!object_data)` is not correct anymore.
The remaining question is: should we need to accept 0 as a valid TCP
port? Can it be used? How does the kernel handle it?
I agree that must be a check for port 0 in add_rule_net_service(),
cause unlike most port numbers, port 0 is a reserved port in TCP/IP
networking, meaning that it should not be used in TCP or UDP messages.
Also network traffic sent across the internet to hosts listening on port
0 might be generated from network attackers or accidentally by
applications programmed incorrectly.
Source: https://www.lifewire.com/port-0-in-tcp-and-udp-818145
return NULL;
- node = ruleset->root.rb_node;
+
+ switch (rule_type) {
+ case LANDLOCK_RULE_PATH_BENEATH:
+ node = ruleset->root_inode.rb_node;
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
This is a bug. There is no check for such value. You need to check
and update all call sites to catch such errors. Same for all new
use of ERR_PTR().
Sorry, I did not get your point.
Do you mean I should check the correctness of rule_type in above
function which calls landlock_find_rule() ??? Why can't I add such
check here?
landlock_find_rule() only returns NULL or a valid pointer, not an error.
What about incorrect rule_type?? Return NULL? Or final rule_checl
must be in upper function?
This case should never happen anyway. You should return NULL and call
WARN_ON_ONCE(1) just before. The same kind of WARN_ON_ONCE(1) call
should be part of all switch/cases of rule_type (except the two valid
values of course).
Ok. I got it. Thanks.
.
