cifs: fix SID binary to string conversion
The authority fields are supposed to be represented by a single 48-bit
value. It's also supposed to represent the value as hex if it's equal to
or greater than 2^32. This is documented in MS-DTYP, section 2.4.2.1.
Also, fix up the max string length to account for this fix.
Acked-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index 8dd9212..75c1ee69 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -94,6 +94,7 @@
int i, len;
unsigned int saval;
char *sidstr, *strptr;
+ unsigned long long id_auth_val;
/* 3 bytes for prefix */
sidstr = kmalloc(3 + SID_STRING_BASE_SIZE +
@@ -107,12 +108,24 @@
sidptr->revision);
strptr += len;
- for (i = 0; i < NUM_AUTHS; ++i) {
- if (sidptr->authority[i]) {
- len = sprintf(strptr, "-%hhu", sidptr->authority[i]);
- strptr += len;
- }
- }
+ /* The authority field is a single 48-bit number */
+ id_auth_val = (unsigned long long)sidptr->authority[5];
+ id_auth_val |= (unsigned long long)sidptr->authority[4] << 8;
+ id_auth_val |= (unsigned long long)sidptr->authority[3] << 16;
+ id_auth_val |= (unsigned long long)sidptr->authority[2] << 24;
+ id_auth_val |= (unsigned long long)sidptr->authority[1] << 32;
+ id_auth_val |= (unsigned long long)sidptr->authority[0] << 48;
+
+ /*
+ * MS-DTYP states that if the authority is >= 2^32, then it should be
+ * expressed as a hex value.
+ */
+ if (id_auth_val <= UINT_MAX)
+ len = sprintf(strptr, "-%llu", id_auth_val);
+ else
+ len = sprintf(strptr, "-0x%llx", id_auth_val);
+
+ strptr += len;
for (i = 0; i < sidptr->num_subauth; ++i) {
saval = le32_to_cpu(sidptr->sub_auth[i]);