[PATCH v1 12/17] Call sort_pacl_range() for decoded POSIX draft ACLs

[rick.macklem@gmail.com]

From: Rick Macklem <rmacklem@uoguelph.ca>

posix_valid_check() expects the ACEs in a POSIX draft ACL
to be sorted, so sort them.  Since sort_pacl_range() uses bubble
sort, it will only make a single pass through the ACEs if they
are already sorted, which will often be the case.

Signed-off-by: Rick Macklem <rmacklem@uoguelph.ca>
---
 fs/nfsd/nfs4xdr.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index d12e479c18d3..72530203e985 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -483,6 +483,16 @@ nfsd4_decode_posix_acl(struct nfsd4_compoundargs *argp, struct posix_acl **acl)
 		}
 	}
 
+	/*
+	 * posix_acl_valid() requires the ACEs to be sorted.
+	 * If they are already sorted, sort_pacl_range() will return
+	 * after one pass through the ACEs, since it implements bubble sort.
+	 * Note that a count == 0 is used to delete a POSIX ACL and a count
+	 * of 1 or 2 will always be found invalid by posix_acl_valid().
+	 */
+	if (count >= 3)
+		sort_pacl_range(*acl, 0, count - 1);
+
 	return nfs_ok;
 }
 
-- 
2.49.0