Merge pull request #9919 from hmac/hmac/ar-associations

Ruby: ActiveRecord associations
This commit is contained in:
Harry Maclean
2022-08-10 11:13:39 +12:00
committed by GitHub
4 changed files with 369 additions and 0 deletions

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@@ -0,0 +1,6 @@
---
category: minorAnalysis
---
* Calls to methods generated by ActiveRecord associations are now recognised as
instantiations of ActiveRecord objects. This increases the sensitivity of
queries such as `rb/sql-injection` and `rb/stored-xss`.

View File

@@ -516,3 +516,177 @@ private module Persistence {
override DataFlow::Node getValue() { assignNode.getRhs() = result.asExpr() }
}
}
/**
* A method call inside an ActiveRecord model class that establishes an
* association between this model and another model.
*
* ```rb
* class User
* has_many :posts
* has_one :profile
* end
* ```
*/
private class ActiveRecordAssociation extends DataFlow::CallNode {
private ActiveRecordModelClass modelClass;
ActiveRecordAssociation() {
not exists(this.asExpr().getExpr().getEnclosingMethod()) and
this.asExpr().getExpr().getEnclosingModule() = modelClass and
this.getMethodName() = ["has_one", "has_many", "belongs_to", "has_and_belongs_to_many"]
}
/**
* Gets the class which declares this association.
* For example, in
* ```rb
* class User
* has_many :posts
* end
* ```
* the source class is `User`.
*/
ActiveRecordModelClass getSourceClass() { result = modelClass }
/**
* Gets the class which this association refers to.
* For example, in
* ```rb
* class User
* has_many :posts
* end
* ```
* the target class is `Post`.
*/
ActiveRecordModelClass getTargetClass() {
result.getName().toLowerCase() = this.getTargetModelName()
}
/**
* Gets the (lowercase) name of the model this association targets.
* For example, in `has_many :posts`, this is `post`.
*/
string getTargetModelName() {
exists(string s |
s = this.getArgument(0).asExpr().getExpr().getConstantValue().getStringlikeValue()
|
// has_one :profile
// belongs_to :user
this.isSingular() and
result = s
or
// has_many :posts
// has_many :stories
this.isCollection() and
pluralize(result) = s
)
}
/** Holds if this association is one-to-one */
predicate isSingular() { this.getMethodName() = ["has_one", "belongs_to"] }
/** Holds if this association is one-to-many or many-to-many */
predicate isCollection() { this.getMethodName() = ["has_many", "has_and_belongs_to_many"] }
}
/**
* Converts `input` to plural form.
*/
bindingset[input]
bindingset[result]
private string pluralize(string input) {
exists(string stem | stem + "y" = input | result = stem + "ies")
or
result = input + "s"
}
/**
* A call to a method generated by an ActiveRecord association.
* These yield ActiveRecord collection proxies, which act like collections but
* add some additional methods.
* We exclude `<model>_changed?` and `<model>_previously_changed?` because these
* do not yield ActiveRecord instances.
* https://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html
*/
private class ActiveRecordAssociationMethodCall extends DataFlow::CallNode {
ActiveRecordAssociation assoc;
ActiveRecordAssociationMethodCall() {
exists(string model | model = assoc.getTargetModelName() |
this.getReceiver().(ActiveRecordInstance).getClass() = assoc.getSourceClass() and
(
assoc.isCollection() and
(
this.getMethodName() = pluralize(model) + ["", "="]
or
this.getMethodName() = "<<"
or
this.getMethodName() = model + ["_ids", "_ids="]
)
or
assoc.isSingular() and
(
this.getMethodName() = model + ["", "="] or
this.getMethodName() = ["build_", "reload_"] + model or
this.getMethodName() = "create_" + model + ["!", ""]
)
)
)
}
ActiveRecordAssociation getAssociation() { result = assoc }
}
/**
* A method call on an ActiveRecord collection proxy that yields one or more
* ActiveRecord instances.
* Example:
* ```rb
* class User < ActiveRecord::Base
* has_many :posts
* end
*
* User.new.posts.create
* ```
* https://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html
*/
private class ActiveRecordCollectionProxyMethodCall extends DataFlow::CallNode {
ActiveRecordCollectionProxyMethodCall() {
this.getMethodName() =
[
"push", "concat", "build", "create", "create!", "delete", "delete_all", "destroy",
"destroy_all", "find", "distinct", "reset", "reload"
] and
(
this.getReceiver().(ActiveRecordAssociationMethodCall).getAssociation().isCollection()
or
exists(ActiveRecordCollectionProxyMethodCall receiver | receiver = this.getReceiver() |
receiver.getAssociation().isCollection() and
receiver.getMethodName() = ["reset", "reload", "distinct"]
)
)
}
ActiveRecordAssociation getAssociation() {
result = this.getReceiver().(ActiveRecordAssociationMethodCall).getAssociation()
}
}
/**
* A call to an association method which yields ActiveRecord instances.
*/
private class ActiveRecordAssociationModelInstantiation extends ActiveRecordModelInstantiation instanceof ActiveRecordAssociationMethodCall {
override ActiveRecordModelClass getClass() {
result = this.(ActiveRecordAssociationMethodCall).getAssociation().getTargetClass()
}
}
/**
* A call to a method on a collection proxy which yields ActiveRecord instances.
*/
private class ActiveRecordCollectionProxyModelInstantiation extends ActiveRecordModelInstantiation instanceof ActiveRecordCollectionProxyMethodCall {
override ActiveRecordModelClass getClass() {
result = this.(ActiveRecordCollectionProxyMethodCall).getAssociation().getTargetClass()
}
}

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@@ -2,15 +2,102 @@ activeRecordModelClasses
| ActiveRecord.rb:1:1:3:3 | UserGroup |
| ActiveRecord.rb:5:1:15:3 | User |
| ActiveRecord.rb:17:1:21:3 | Admin |
| associations.rb:1:1:3:3 | Author |
| associations.rb:5:1:9:3 | Post |
| associations.rb:11:1:13:3 | Tag |
| associations.rb:15:1:17:3 | Comment |
activeRecordInstances
| ActiveRecord.rb:9:5:9:68 | call to find |
| ActiveRecord.rb:13:5:13:40 | call to find_by |
| ActiveRecord.rb:13:5:13:46 | call to users |
| ActiveRecord.rb:36:5:36:30 | call to find_by_name |
| ActiveRecord.rb:55:5:57:7 | if ... |
| ActiveRecord.rb:55:43:56:40 | then ... |
| ActiveRecord.rb:56:7:56:40 | call to find_by |
| ActiveRecord.rb:60:5:60:33 | call to find_by |
| ActiveRecord.rb:62:5:62:34 | call to find |
| associations.rb:19:1:19:20 | ... = ... |
| associations.rb:19:1:19:20 | ... = ... |
| associations.rb:19:11:19:20 | call to new |
| associations.rb:21:1:21:28 | ... = ... |
| associations.rb:21:1:21:28 | ... = ... |
| associations.rb:21:9:21:15 | author1 |
| associations.rb:21:9:21:21 | call to posts |
| associations.rb:21:9:21:28 | call to create |
| associations.rb:23:1:23:32 | ... = ... |
| associations.rb:23:12:23:16 | post1 |
| associations.rb:23:12:23:25 | call to comments |
| associations.rb:23:12:23:32 | call to create |
| associations.rb:25:1:25:22 | ... = ... |
| associations.rb:25:1:25:22 | ... = ... |
| associations.rb:25:11:25:15 | post1 |
| associations.rb:25:11:25:22 | call to author |
| associations.rb:27:1:27:28 | ... = ... |
| associations.rb:27:1:27:28 | ... = ... |
| associations.rb:27:9:27:15 | author2 |
| associations.rb:27:9:27:21 | call to posts |
| associations.rb:27:9:27:28 | call to create |
| associations.rb:29:1:29:7 | author2 |
| associations.rb:29:1:29:13 | call to posts |
| associations.rb:29:1:29:22 | ... << ... |
| associations.rb:29:18:29:22 | post2 |
| associations.rb:31:1:31:5 | post1 |
| associations.rb:31:1:31:12 | __synth__0 |
| associations.rb:31:1:31:12 | call to author= |
| associations.rb:31:1:31:22 | ... |
| associations.rb:31:16:31:22 | ... = ... |
| associations.rb:31:16:31:22 | ... = ... |
| associations.rb:31:16:31:22 | author2 |
| associations.rb:35:1:35:5 | post2 |
| associations.rb:35:1:35:14 | call to comments |
| associations.rb:35:1:35:21 | call to create |
| associations.rb:37:1:37:7 | author1 |
| associations.rb:37:1:37:13 | call to posts |
| associations.rb:37:1:37:20 | call to reload |
| associations.rb:37:1:37:27 | call to create |
| associations.rb:39:1:39:5 | post1 |
| associations.rb:40:1:40:5 | post1 |
| associations.rb:42:1:42:7 | author1 |
| associations.rb:42:1:42:13 | call to posts |
| associations.rb:42:1:42:25 | call to push |
| associations.rb:42:20:42:24 | post2 |
| associations.rb:43:1:43:7 | author1 |
| associations.rb:43:1:43:13 | call to posts |
| associations.rb:43:1:43:27 | call to concat |
| associations.rb:43:22:43:26 | post2 |
| associations.rb:44:1:44:7 | author1 |
| associations.rb:44:1:44:13 | call to posts |
| associations.rb:44:1:44:19 | call to build |
| associations.rb:45:1:45:7 | author1 |
| associations.rb:45:1:45:13 | call to posts |
| associations.rb:45:1:45:20 | call to create |
| associations.rb:46:1:46:7 | author1 |
| associations.rb:46:1:46:13 | call to posts |
| associations.rb:46:1:46:21 | call to create! |
| associations.rb:47:1:47:7 | author1 |
| associations.rb:47:1:47:13 | call to posts |
| associations.rb:47:1:47:20 | call to delete |
| associations.rb:48:1:48:7 | author1 |
| associations.rb:48:1:48:13 | call to posts |
| associations.rb:48:1:48:24 | call to delete_all |
| associations.rb:49:1:49:7 | author1 |
| associations.rb:49:1:49:13 | call to posts |
| associations.rb:49:1:49:21 | call to destroy |
| associations.rb:50:1:50:7 | author1 |
| associations.rb:50:1:50:13 | call to posts |
| associations.rb:50:1:50:25 | call to destroy_all |
| associations.rb:51:1:51:7 | author1 |
| associations.rb:51:1:51:13 | call to posts |
| associations.rb:51:1:51:22 | call to distinct |
| associations.rb:51:1:51:36 | call to find |
| associations.rb:52:1:52:7 | author1 |
| associations.rb:52:1:52:13 | call to posts |
| associations.rb:52:1:52:19 | call to reset |
| associations.rb:52:1:52:33 | call to find |
| associations.rb:53:1:53:7 | author1 |
| associations.rb:53:1:53:13 | call to posts |
| associations.rb:53:1:53:20 | call to reload |
| associations.rb:53:1:53:34 | call to find |
activeRecordSqlExecutionRanges
| ActiveRecord.rb:9:33:9:67 | "name='#{...}' and pass='#{...}'" |
| ActiveRecord.rb:19:16:19:24 | condition |
@@ -53,6 +140,13 @@ activeRecordModelClassMethodCalls
| ActiveRecord.rb:92:5:92:71 | call to update |
| ActiveRecord.rb:98:13:98:54 | call to annotate |
| ActiveRecord.rb:102:13:102:77 | call to annotate |
| associations.rb:2:3:2:17 | call to has_many |
| associations.rb:6:3:6:20 | call to belongs_to |
| associations.rb:7:3:7:20 | call to has_many |
| associations.rb:8:3:8:31 | call to has_and_belongs_to_many |
| associations.rb:12:3:12:32 | call to has_and_belongs_to_many |
| associations.rb:16:3:16:18 | call to belongs_to |
| associations.rb:19:11:19:20 | call to new |
potentiallyUnsafeSqlExecutingMethodCall
| ActiveRecord.rb:9:5:9:68 | call to find |
| ActiveRecord.rb:19:5:19:25 | call to destroy_by |
@@ -68,10 +162,51 @@ potentiallyUnsafeSqlExecutingMethodCall
activeRecordModelInstantiations
| ActiveRecord.rb:9:5:9:68 | call to find | ActiveRecord.rb:5:1:15:3 | User |
| ActiveRecord.rb:13:5:13:40 | call to find_by | ActiveRecord.rb:1:1:3:3 | UserGroup |
| ActiveRecord.rb:13:5:13:46 | call to users | ActiveRecord.rb:5:1:15:3 | User |
| ActiveRecord.rb:36:5:36:30 | call to find_by_name | ActiveRecord.rb:5:1:15:3 | User |
| ActiveRecord.rb:56:7:56:40 | call to find_by | ActiveRecord.rb:5:1:15:3 | User |
| ActiveRecord.rb:60:5:60:33 | call to find_by | ActiveRecord.rb:5:1:15:3 | User |
| ActiveRecord.rb:62:5:62:34 | call to find | ActiveRecord.rb:5:1:15:3 | User |
| associations.rb:19:11:19:20 | call to new | associations.rb:1:1:3:3 | Author |
| associations.rb:21:9:21:21 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:21:9:21:28 | call to create | associations.rb:5:1:9:3 | Post |
| associations.rb:23:12:23:25 | call to comments | associations.rb:15:1:17:3 | Comment |
| associations.rb:23:12:23:32 | call to create | associations.rb:15:1:17:3 | Comment |
| associations.rb:25:11:25:22 | call to author | associations.rb:1:1:3:3 | Author |
| associations.rb:27:9:27:21 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:27:9:27:28 | call to create | associations.rb:5:1:9:3 | Post |
| associations.rb:29:1:29:13 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:29:1:29:22 | ... << ... | associations.rb:11:1:13:3 | Tag |
| associations.rb:29:1:29:22 | ... << ... | associations.rb:15:1:17:3 | Comment |
| associations.rb:31:1:31:12 | call to author= | associations.rb:1:1:3:3 | Author |
| associations.rb:35:1:35:14 | call to comments | associations.rb:15:1:17:3 | Comment |
| associations.rb:35:1:35:21 | call to create | associations.rb:15:1:17:3 | Comment |
| associations.rb:37:1:37:13 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:37:1:37:20 | call to reload | associations.rb:5:1:9:3 | Post |
| associations.rb:42:1:42:13 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:42:1:42:25 | call to push | associations.rb:5:1:9:3 | Post |
| associations.rb:43:1:43:13 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:43:1:43:27 | call to concat | associations.rb:5:1:9:3 | Post |
| associations.rb:44:1:44:13 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:44:1:44:19 | call to build | associations.rb:5:1:9:3 | Post |
| associations.rb:45:1:45:13 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:45:1:45:20 | call to create | associations.rb:5:1:9:3 | Post |
| associations.rb:46:1:46:13 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:46:1:46:21 | call to create! | associations.rb:5:1:9:3 | Post |
| associations.rb:47:1:47:13 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:47:1:47:20 | call to delete | associations.rb:5:1:9:3 | Post |
| associations.rb:48:1:48:13 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:48:1:48:24 | call to delete_all | associations.rb:5:1:9:3 | Post |
| associations.rb:49:1:49:13 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:49:1:49:21 | call to destroy | associations.rb:5:1:9:3 | Post |
| associations.rb:50:1:50:13 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:50:1:50:25 | call to destroy_all | associations.rb:5:1:9:3 | Post |
| associations.rb:51:1:51:13 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:51:1:51:22 | call to distinct | associations.rb:5:1:9:3 | Post |
| associations.rb:52:1:52:13 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:52:1:52:19 | call to reset | associations.rb:5:1:9:3 | Post |
| associations.rb:53:1:53:13 | call to posts | associations.rb:5:1:9:3 | Post |
| associations.rb:53:1:53:20 | call to reload | associations.rb:5:1:9:3 | Post |
persistentWriteAccesses
| ActiveRecord.rb:72:5:72:24 | call to create | ActiveRecord.rb:72:18:72:23 | call to params |
| ActiveRecord.rb:76:5:76:66 | call to create | ActiveRecord.rb:76:24:76:36 | ...[...] |
@@ -82,3 +217,4 @@ persistentWriteAccesses
| ActiveRecord.rb:88:5:88:69 | call to update | ActiveRecord.rb:88:27:88:39 | ...[...] |
| ActiveRecord.rb:88:5:88:69 | call to update | ActiveRecord.rb:88:52:88:68 | ...[...] |
| ActiveRecord.rb:92:5:92:71 | call to update | ActiveRecord.rb:92:21:92:70 | call to [] |
| associations.rb:31:16:31:22 | ... = ... | associations.rb:31:16:31:22 | author2 |

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@@ -0,0 +1,53 @@
class Author < ActiveRecord::Base
has_many :posts
end
class Post < ActiveRecord::Base
belongs_to :author
has_many :comments
has_and_belongs_to_many :tags
end
class Tag < ActiveRecord::Base
has_and_belongs_to_many :posts
end
class Comment < ActiveRecord::Base
belongs_to :post
end
author1 = Author.new
post1 = author1.posts.create
comment1 = post1.comments.create
author2 = post1.author
post2 = author2.posts.create
author2.posts << post2
post1.author = author2
# The final method call in this chain should not be recognised as an
# instantiation.
post2.comments.create.create
author1.posts.reload.create
post1.build_tag
post1.build_tag
author1.posts.push(post2)
author1.posts.concat(post2)
author1.posts.build
author1.posts.create
author1.posts.create!
author1.posts.delete
author1.posts.delete_all
author1.posts.destroy
author1.posts.destroy_all
author1.posts.distinct.find(post_id)
author1.posts.reset.find(post_id)
author1.posts.reload.find(post_id)