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, 4 insertions, 24 deletions

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index 78eed72f3af0..1d377b7f2860 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -33,25 +33,6 @@
 #include "cifsproto.h"
 #include "cifs_debug.h"
 
-static struct key_acl cifs_idmap_key_acl = {
-	.usage	= REFCOUNT_INIT(1),
-	.nr_ace	= 2,
-	.possessor_viewable = true,
-	.aces = {
-		KEY_POSSESSOR_ACE(KEY_ACE_VIEW | KEY_ACE_SEARCH | KEY_ACE_READ),
-		KEY_OWNER_ACE(KEY_ACE_VIEW),
-	}
-};
-
-static struct key_acl cifs_idmap_keyring_acl = {
-	.usage	= REFCOUNT_INIT(1),
-	.nr_ace	= 2,
-	.aces = {
-		KEY_POSSESSOR_ACE(KEY_ACE_SEARCH | KEY_ACE_WRITE),
-		KEY_OWNER_ACE(KEY_ACE_VIEW | KEY_ACE_READ),
-	}
-};
-
 /* security id for everyone/world system group */
 static const struct cifs_sid sid_everyone = {
 	1, 1, {0, 0, 0, 0, 0, 1}, {0} };
@@ -317,8 +298,7 @@ id_to_sid(unsigned int cid, uint sidtype, struct cifs_sid *ssid)
 
 	rc = 0;
 	saved_cred = override_creds(root_cred);
-	sidkey = request_key(&cifs_idmap_key_type, desc, "",
-			     &cifs_idmap_key_acl);
+	sidkey = request_key(&cifs_idmap_key_type, desc, "");
 	if (IS_ERR(sidkey)) {
 		rc = -EINVAL;
 		cifs_dbg(FYI, "%s: Can't map %cid %u to a SID\n",
@@ -423,8 +403,7 @@ try_upcall_to_get_id:
 		return -ENOMEM;
 
 	saved_cred = override_creds(root_cred);
-	sidkey = request_key(&cifs_idmap_key_type, sidstr, "",
-			     &cifs_idmap_key_acl);
+	sidkey = request_key(&cifs_idmap_key_type, sidstr, "");
 	if (IS_ERR(sidkey)) {
 		rc = -EINVAL;
 		cifs_dbg(FYI, "%s: Can't map SID %s to a %cid\n",
@@ -502,7 +481,8 @@ init_cifs_idmap(void)
 
 	keyring = keyring_alloc(".cifs_idmap",
 				GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
-				&cifs_idmap_keyring_acl,
+				(KEY_POS_ALL & ~KEY_POS_SETATTR) |
+				KEY_USR_VIEW | KEY_USR_READ,
 				KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
 	if (IS_ERR(keyring)) {
 		ret = PTR_ERR(keyring);