cifs: Use mask of ACEs for SID Everyone to calculate all three permissions user, group, and other

If a DACL has entries for ACEs for SID Everyone and Authenticated Users,
factor in mask in respective entries during calculation of permissions
for all three, user, group, and other.

http://technet.microsoft.com/en-us/library/bb463216.aspx

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index a437ec391a01..1e7636b145a8 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -41,9 +41,12 @@ static struct cifs_wksid wksidarr[NUM_WK_SIDS] = {
 ;
 
 
-/* security id for everyone */
+/* security id for everyone/world system group */
 static const struct cifs_sid sid_everyone = {
         1, 1, {0, 0, 0, 0, 0, 1}, {0} };
+/* security id for Authenticated Users system group */
+static const struct cifs_sid sid_authusers = {
+        1, 1, {0, 0, 0, 0, 0, 5}, {11} };
 /* group users */
 static const struct cifs_sid sid_user = {1, 2 , {0, 0, 0, 0, 0, 5}, {} };
 
@@ -365,7 +368,7 @@ static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
         if (num_aces  > 0) {
                 umode_t user_mask = S_IRWXU;
                 umode_t group_mask = S_IRWXG;
-                umode_t other_mask = S_IRWXO;
+                umode_t other_mask = S_IRWXU | S_IRWXG | S_IRWXO;
 
                 ppace = kmalloc(num_aces * sizeof(struct cifs_ace *),
                                 GFP_KERNEL);
@@ -390,6 +393,12 @@ static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
                                                      ppace[i]->type,
                                                      &fattr->cf_mode,
                                                      &other_mask);
+                        if (compare_sids(&(ppace[i]->sid), &sid_authusers))
+                                access_flags_to_mode(ppace[i]->access_req,
+                                                     ppace[i]->type,
+                                                     &fattr->cf_mode,
+                                                     &other_mask);
+
 
 /*                      memcpy((void *)(&(cifscred->aces[i])),
                                 (void *)ppace[i],