smbd: check for stale pid in get_lease_type()

If leases_db_get() failed the leases_db record might have been cleaned up for
stale processes. Check if the share-mode-entry owner is stale in this case and
return a 0 lease state. In any other case, log a debug messages and panic.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14428

Signed-off-by: Ralph Boehme <slow@samba.org>
Autobuild-User(master): Stefan Metzmacher <metze@samba.org>
Autobuild-Date(master): Thu Jul  2 16:45:42 UTC 2020 on sn-devel-184

diff --git a/source3/smbd/oplock.c b/source3/smbd/oplock.c
index 97ab05b2ba67d5d16cf5316f90d2f7385125c57b..1c1510f3aabccc95dc11b4e03a13f8ae151a59e6 100644 (file)
--- a/source3/smbd/oplock.c
+++ b/source3/smbd/oplock.c
@@ -171,6 +171,8 @@ static void downgrade_file_oplock(files_struct *fsp)
 
 uint32_t get_lease_type(struct share_mode_entry *e, struct file_id id)
 {
+       struct GUID_txt_buf guid_strbuf;
+       struct file_id_buf file_id_strbuf;
        NTSTATUS status;
        uint32_t current_state;
 
@@ -187,8 +189,22 @@ uint32_t get_lease_type(struct share_mode_entry *e, struct file_id id)
                               NULL,    /* breaking_to_required */
                               NULL,    /* lease_version */
                               NULL);   /* epoch */
-       SMB_ASSERT(NT_STATUS_IS_OK(status));
-       return current_state;
+       if (NT_STATUS_IS_OK(status)) {
+               return current_state;
+       }
+
+       if (share_entry_stale_pid(e)) {
+               return 0;
+       }
+       DBG_ERR("leases_db_get for client_guid [%s] "
+               "lease_key [%"PRIu64"/%"PRIu64"] "
+               "file_id [%s] failed: %s\n",
+               GUID_buf_string(&e->client_guid, &guid_strbuf),
+               e->lease_key.data[0],
+               e->lease_key.data[1],
+               file_id_str_buf(id, &file_id_strbuf),
+               nt_errstr(status));
+       smb_panic("leases_db_get() failed");
 }
 
 /****************************************************************************