[PATCH] knfsd: nfsd4: fix handling of directories without default ACLs

When setting an ACL that lacks inheritable ACEs on a directory, we should set
a default ACL of zero length, not a default ACL with all bits denied.

Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 20 insertions, 1 deletions

diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c
index 0a69cce33efe..832673b14587 100644
--- a/fs/nfsd/nfs4acl.c
+++ b/fs/nfsd/nfs4acl.c
@@ -416,6 +416,7 @@ struct posix_ace_state_array {
  * calculated so far: */
 
 struct posix_acl_state {
+        int empty;
         struct posix_ace_state owner;
         struct posix_ace_state group;
         struct posix_ace_state other;
@@ -431,6 +432,7 @@ init_state(struct posix_acl_state *state, int cnt)
         int alloc;
 
         memset(state, 0, sizeof(struct posix_acl_state));
+        state->empty = 1;
         /*
          * In the worst case, each individual acl could be for a distinct
          * named user or group, but we don't no which, so we allocate
@@ -498,6 +500,20 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags)
         int nace;
         int i, error = 0;
 
+        /*
+         * ACLs with no ACEs are treated differently in the inheritable
+         * and effective cases: when there are no inheritable ACEs, we
+         * set a zero-length default posix acl:
+         */
+        if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT)) {
+                pacl = posix_acl_alloc(0, GFP_KERNEL);
+                return pacl ? pacl : ERR_PTR(-ENOMEM);
+        }
+        /*
+         * When there are no effective ACEs, the following will end
+         * up setting a 3-element effective posix ACL with all
+         * permissions zero.
+         */
         nace = 4 + state->users->n + state->groups->n;
         pacl = posix_acl_alloc(nace, GFP_KERNEL);
         if (!pacl)
@@ -613,6 +629,8 @@ static void process_one_v4_ace(struct posix_acl_state *state,
         u32 mask = ace->access_mask;
         int i;
 
+        state->empty = 0;
+
         switch (ace2type(ace)) {
         case ACL_USER_OBJ:
                 if (ace->type == NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE) {
@@ -717,7 +735,8 @@ int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, struct posix_acl **pacl,
                 ret = PTR_ERR(*pacl);
                 goto out_dstate;
         }
-        *dpacl = posix_state_to_acl(&default_acl_state, flags);
+        *dpacl = posix_state_to_acl(&default_acl_state,
+                                                flags | NFS4_ACL_TYPE_DEFAULT);
         if (IS_ERR(*dpacl)) {
                 ret = PTR_ERR(*dpacl);
                 posix_acl_release(*pacl);