Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs"

This reverts merge 0f75ef6a9cff49ff612f7ce0578bced9d0b38325 (and thus
effectively commits

   7a1ade847596 ("keys: Provide KEYCTL_GRANT_PERMISSION")
   2e12256b9a76 ("keys: Replace uid/gid/perm permissions checking with an ACL")

that the merge brought in).

It turns out that it breaks booting with an encrypted volume, and Eric
biggers reports that it also breaks the fscrypt tests [1] and loading of
in-kernel X.509 certificates [2].

The root cause of all the breakage is likely the same, but David Howells
is off email so rather than try to work it out it's getting reverted in
order to not impact the rest of the merge window.

 [1] https://lore.kernel.org/lkml/20190710011559.GA7973@sol.localdomain/
 [2] https://lore.kernel.org/lkml/20190710013225.GB7973@sol.localdomain/

Link: https://lore.kernel.org/lkml/CAHk-=wjxoeMJfeBahnWH=9zShKp2bsVy527vo3_y8HfOdhwAAw@mail.gmail.com/
Reported-by: Eric Biggers <ebiggers@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 18 insertions, 16 deletions

diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 46c5187ce03f..7325f382dbf4 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -135,7 +135,8 @@ static int call_sbin_request_key(struct key *authkey, void *aux)
 
 	cred = get_current_cred();
 	keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred,
-				NULL, KEY_ALLOC_QUOTA_OVERRUN, NULL, NULL);
+				KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ,
+				KEY_ALLOC_QUOTA_OVERRUN, NULL, NULL);
 	put_cred(cred);
 	if (IS_ERR(keyring)) {
 		ret = PTR_ERR(keyring);
@@ -366,11 +367,11 @@ static int construct_alloc_key(struct keyring_search_context *ctx,
 			       struct key *dest_keyring,
 			       unsigned long flags,
 			       struct key_user *user,
-			       struct key_acl *acl,
 			       struct key **_key)
 {
 	struct assoc_array_edit *edit = NULL;
 	struct key *key;
+	key_perm_t perm;
 	key_ref_t key_ref;
 	int ret;
 
@@ -380,9 +381,17 @@ static int construct_alloc_key(struct keyring_search_context *ctx,
 	*_key = NULL;
 	mutex_lock(&user->cons_lock);
 
+	perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
+	perm |= KEY_USR_VIEW;
+	if (ctx->index_key.type->read)
+		perm |= KEY_POS_READ;
+	if (ctx->index_key.type == &key_type_keyring ||
+	    ctx->index_key.type->update)
+		perm |= KEY_POS_WRITE;
+
 	key = key_alloc(ctx->index_key.type, ctx->index_key.description,
 			ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred,
-			acl, flags, NULL);
+			perm, flags, NULL);
 	if (IS_ERR(key))
 		goto alloc_failed;
 
@@ -465,7 +474,6 @@ static struct key *construct_key_and_link(struct keyring_search_context *ctx,
 					  const char *callout_info,
 					  size_t callout_len,
 					  void *aux,
-					  struct key_acl *acl,
 					  struct key *dest_keyring,
 					  unsigned long flags)
 {
@@ -488,7 +496,7 @@ static struct key *construct_key_and_link(struct keyring_search_context *ctx,
 		goto error_put_dest_keyring;
 	}
 
-	ret = construct_alloc_key(ctx, dest_keyring, flags, user, acl, &key);
+	ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key);
 	key_user_put(user);
 
 	if (ret == 0) {
@@ -526,7 +534,6 @@ error:
  * @callout_info: The data to pass to the instantiation upcall (or NULL).
  * @callout_len: The length of callout_info.
  * @aux: Auxiliary data for the upcall.
- * @acl: The ACL to attach if a new key is created.
  * @dest_keyring: Where to cache the key.
  * @flags: Flags to key_alloc().
  *
@@ -554,7 +561,6 @@ struct key *request_key_and_link(struct key_type *type,
 				 const void *callout_info,
 				 size_t callout_len,
 				 void *aux,
-				 struct key_acl *acl,
 				 struct key *dest_keyring,
 				 unsigned long flags)
 {
@@ -629,7 +635,7 @@ struct key *request_key_and_link(struct key_type *type,
 			goto error_free;
 
 		key = construct_key_and_link(&ctx, callout_info, callout_len,
-					     aux, acl, dest_keyring, flags);
+					     aux, dest_keyring, flags);
 	}
 
 error_free:
@@ -672,7 +678,6 @@ EXPORT_SYMBOL(wait_for_key_construction);
  * @description: The searchable description of the key.
  * @domain_tag: The domain in which the key operates.
  * @callout_info: The data to pass to the instantiation upcall (or NULL).
- * @acl: The ACL to attach if a new key is created.
  *
  * As for request_key_and_link() except that it does not add the returned key
  * to a keyring if found, new keys are always allocated in the user's quota,
@@ -685,8 +690,7 @@ EXPORT_SYMBOL(wait_for_key_construction);
 struct key *request_key_tag(struct key_type *type,
 			    const char *description,
 			    struct key_tag *domain_tag,
-			    const char *callout_info,
-			    struct key_acl *acl)
+			    const char *callout_info)
 {
 	struct key *key;
 	size_t callout_len = 0;
@@ -696,7 +700,7 @@ struct key *request_key_tag(struct key_type *type,
 		callout_len = strlen(callout_info);
 	key = request_key_and_link(type, description, domain_tag,
 				   callout_info, callout_len,
-				   NULL, acl, NULL, KEY_ALLOC_IN_QUOTA);
+				   NULL, NULL, KEY_ALLOC_IN_QUOTA);
 	if (!IS_ERR(key)) {
 		ret = wait_for_key_construction(key, false);
 		if (ret < 0) {
@@ -716,7 +720,6 @@ EXPORT_SYMBOL(request_key_tag);
  * @callout_info: The data to pass to the instantiation upcall (or NULL).
  * @callout_len: The length of callout_info.
  * @aux: Auxiliary data for the upcall.
- * @acl: The ACL to attach if a new key is created.
  *
  * As for request_key_and_link() except that it does not add the returned key
  * to a keyring if found and new keys are always allocated in the user's quota.
@@ -729,15 +732,14 @@ struct key *request_key_with_auxdata(struct key_type *type,
 				     struct key_tag *domain_tag,
 				     const void *callout_info,
 				     size_t callout_len,
-				     void *aux,
-				     struct key_acl *acl)
+				     void *aux)
 {
 	struct key *key;
 	int ret;
 
 	key = request_key_and_link(type, description, domain_tag,
 				   callout_info, callout_len,
-				   aux, acl, NULL, KEY_ALLOC_IN_QUOTA);
+				   aux, NULL, KEY_ALLOC_IN_QUOTA);
 	if (!IS_ERR(key)) {
 		ret = wait_for_key_construction(key, false);
 		if (ret < 0) {