knfsd: nfsd4: fix handling of acl errrors

nfs4_acl_nfsv4_to_posix() returns an error and returns any posix acls
calculated in two caller-provided pointers.  It was setting these pointers to
-errno in some error cases, resulting in nfsd4_set_nfs4_acl() calling
posix_acl_release() with a -errno as an argument.

Fix both the caller and the callee, by modifying nfsd4_set_nfs4_acl() to
stop relying on the passed-in-pointers being left as NULL in the error
case, and by modifying nfs4_acl_nfsv4_to_posix() to stop returning
garbage in those pointers.

Thanks to Alex Soule for reporting the bug.

Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Cc: Alexander Soule <soule@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, 3 insertions, 0 deletions

diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c
index 4adb5ee4759b..b6ed38380ab8 100644
--- a/fs/nfsd/nfs4acl.c
+++ b/fs/nfsd/nfs4acl.c
@@ -737,13 +737,16 @@ int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, struct posix_acl **pacl,
         *pacl = posix_state_to_acl(&effective_acl_state, flags);
         if (IS_ERR(*pacl)) {
                 ret = PTR_ERR(*pacl);
+                *pacl = NULL;
                 goto out_dstate;
         }
         *dpacl = posix_state_to_acl(&default_acl_state,
                                                 flags | NFS4_ACL_TYPE_DEFAULT);
         if (IS_ERR(*dpacl)) {
                 ret = PTR_ERR(*dpacl);
+                *dpacl = NULL;
                 posix_acl_release(*pacl);
+                *pacl = NULL;
                 goto out_dstate;
         }
         sort_pacl(*pacl);