BUG: vfs-cifs hangs from windows explorer: access denied: cause write size

Amin Azez azez at ufomechanic.net
Thu Nov 29 12:19:36 GMT 2007

Well this is the patch that proves the bug; sadly the client doesn't
take the hint, and keeps sending large writes, but at least the files
get saved.

I/we still need to work out how to propagate the real limit.

I think we ought to have this patch as a safety net; and if not the
solution, at least the warning.

-------------- next part --------------
diff --git a/source/ntvfs/cifs/vfs_cifs.c b/source/ntvfs/cifs/vfs_cifs.c
index bd1997f..f34633c 100644
--- a/source/ntvfs/cifs/vfs_cifs.c
+++ b/source/ntvfs/cifs/vfs_cifs.c
@@ -673,6 +673,17 @@ static NTSTATUS cvfs_write(struct ntvfs_module_context *ntvfs,
+	/* If the write is too big, then reduce it, the response says how much
+	   was written anyway... Session negotiation time should set the client 
+	   limit to something matching the proxied server */
+	if (io->generic.in.count > 
+		private->tree->session->transport->negotiate.max_xmit) {
+		DEBUG(1,("Client sending too-big write sized %d, negotiated limit %d\n",
+				 io->generic.in.count,
+				 private->tree->session->transport->negotiate.max_xmit));
+		io->generic.in.count=private->tree->session->transport->negotiate.max_xmit;
+	}
 	if (!(req->async_states->state & NTVFS_ASYNC_STATE_MAY_ASYNC)) {
 		return smb_raw_write(private->tree, io);

More information about the samba-technical mailing list