3/22/2022 4:24 PM, Mickaël Salaün пишет:

On 22/03/2022 13:33, Konstantin Meskhidze wrote:

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3/18/2022 9:33 PM, Mickaël Salaün пишет:

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On 17/03/2022 15:29, Konstantin Meskhidze wrote:

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3/16/2022 11:27 AM, Mickaël Salaün пишет:

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On 09/03/2022 14:44, Konstantin Meskhidze wrote:

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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 <redacted>
---

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@@ -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.

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@@ -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

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          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.

.