Merge tag '5.3-rc3-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "Six small SMB3 fixes, two for stable"

* tag '5.3-rc3-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  SMB3: Kernel oops mounting a encryptData share with CONFIG_DEBUG_VIRTUAL
  smb3: update TODO list of missing features
  smb3: send CAP_DFS capability during session setup
  SMB3: Fix potential memory leak when processing compound chain
  SMB3: Fix deadlock in validate negotiate hits reconnect
  cifs: fix rmmod regression in cifs.ko caused by force_sig changes

3 files changed, 33 insertions, 14 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index a4830ced0f98..a15a6e738eb5 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1113,6 +1113,7 @@ cifs_demultiplex_thread(void *p)
 		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 
 	set_freezable();
+	allow_signal(SIGKILL);
 	while (server->tcpStatus != CifsExiting) {
 		if (try_to_freeze())
 			continue;
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index a5bc1b671c12..64a5864127be 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3489,7 +3489,15 @@ fill_transform_hdr(struct smb2_transform_hdr *tr_hdr, unsigned int orig_len,
 static inline void smb2_sg_set_buf(struct scatterlist *sg, const void *buf,
 				   unsigned int buflen)
 {
-	sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
+	void *addr;
+	/*
+	 * VMAP_STACK (at least) puts stack into the vmalloc address space
+	 */
+	if (is_vmalloc_addr(buf))
+		addr = vmalloc_to_page(buf);
+	else
+		addr = virt_to_page(buf);
+	sg_set_page(sg, addr, buflen, offset_in_page(buf));
 }
 
 /* Assumes the first rqst has a transform header as the first iov.
@@ -4070,7 +4078,6 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
 {
 	int ret, length;
 	char *buf = server->smallbuf;
-	char *tmpbuf;
 	struct smb2_sync_hdr *shdr;
 	unsigned int pdu_length = server->pdu_size;
 	unsigned int buf_size;
@@ -4100,18 +4107,15 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
 		return length;
 
 	next_is_large = server->large_buf;
- one_more:
+one_more:
 	shdr = (struct smb2_sync_hdr *)buf;
 	if (shdr->NextCommand) {
-		if (next_is_large) {
-			tmpbuf = server->bigbuf;
+		if (next_is_large)
 			next_buffer = (char *)cifs_buf_get();
-		} else {
-			tmpbuf = server->smallbuf;
+		else
 			next_buffer = (char *)cifs_small_buf_get();
-		}
 		memcpy(next_buffer,
-		       tmpbuf + le32_to_cpu(shdr->NextCommand),
+		       buf + le32_to_cpu(shdr->NextCommand),
 		       pdu_length - le32_to_cpu(shdr->NextCommand));
 	}
 
@@ -4140,12 +4144,21 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
 		pdu_length -= le32_to_cpu(shdr->NextCommand);
 		server->large_buf = next_is_large;
 		if (next_is_large)
-			server->bigbuf = next_buffer;
+			server->bigbuf = buf = next_buffer;
 		else
-			server->smallbuf = next_buffer;
-
-		buf += le32_to_cpu(shdr->NextCommand);
+			server->smallbuf = buf = next_buffer;
 		goto one_more;
+	} else if (ret != 0) {
+		/*
+		 * ret != 0 here means that we didn't get to handle_mid() thus
+		 * server->smallbuf and server->bigbuf are still valid. We need
+		 * to free next_buffer because it is not going to be used
+		 * anywhere.
+		 */
+		if (next_is_large)
+			free_rsp_buf(CIFS_LARGE_BUFFER, next_buffer);
+		else
+			free_rsp_buf(CIFS_SMALL_BUFFER, next_buffer);
 	}
 
 	return ret;
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index c8cd7b6cdda2..31e4a1b0b170 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -252,7 +252,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
 	if (tcon == NULL)
 		return 0;
 
-	if (smb2_command == SMB2_TREE_CONNECT)
+	if (smb2_command == SMB2_TREE_CONNECT || smb2_command == SMB2_IOCTL)
 		return 0;
 
 	if (tcon->tidStatus == CifsExiting) {
@@ -1196,7 +1196,12 @@ SMB2_sess_alloc_buffer(struct SMB2_sess_data *sess_data)
 	else
 		req->SecurityMode = 0;
 
+#ifdef CONFIG_CIFS_DFS_UPCALL
+	req->Capabilities = cpu_to_le32(SMB2_GLOBAL_CAP_DFS);
+#else
 	req->Capabilities = 0;
+#endif /* DFS_UPCALL */
+
 	req->Channel = 0; /* MBZ */
 
 	sess_data->iov[0].iov_base = (char *)req;