6 smb3 server fixes, including one for RDMA, one for improving NTLMSSP auth, one for improved buffer validation, one for stable

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Merge tag '5.17-rc3-ksmbd-server-fixes' of git://git.samba.org/ksmbd

Pull ksmbd server fixes from Steve French:

 - NTLMSSP authentication improvement

 - RDMA (smbdirect) fix allowing broader set of NICs to be supported

 - improved buffer validation

 - additional small fixes, including a posix extensions fix for stable

* tag '5.17-rc3-ksmbd-server-fixes' of git://git.samba.org/ksmbd:
  ksmbd: add support for key exchange
  ksmbd: reduce smb direct max read/write size
  ksmbd: don't align last entry offset in smb2 query directory
  ksmbd: fix same UniqueId for dot and dotdot entries
  ksmbd: smbd: validate buffer descriptor structures
  ksmbd: fix SMB 3.11 posix extension mount failure

fs/Kconfig

@@ -369,8 +369,8 @@ source "fs/ksmbd/Kconfig"
 
 config SMBFS_COMMON
 	tristate
-	default y if CIFS=y
+	default y if CIFS=y || SMB_SERVER=y
-	default m if CIFS=m
+	default m if CIFS=m || SMB_SERVER=m
 
 source "fs/coda/Kconfig"
 source "fs/afs/Kconfig"

fs/ksmbd/auth.c

@@ -29,6 +29,7 @@
 #include "mgmt/user_config.h"
 #include "crypto_ctx.h"
 #include "transport_ipc.h"
+#include "../smbfs_common/arc4.h"
 
 /*
  * Fixed format data defining GSS header and fixed string
@@ -336,6 +337,29 @@ int ksmbd_decode_ntlmssp_auth_blob(struct authenticate_message *authblob,
 				nt_len - CIFS_ENCPWD_SIZE,
 				domain_name, conn->ntlmssp.cryptkey);
 	kfree(domain_name);
+
+	/* The recovered secondary session key */
+	if (conn->ntlmssp.client_flags & NTLMSSP_NEGOTIATE_KEY_XCH) {
+		struct arc4_ctx *ctx_arc4;
+		unsigned int sess_key_off, sess_key_len;
+
+		sess_key_off = le32_to_cpu(authblob->SessionKey.BufferOffset);
+		sess_key_len = le16_to_cpu(authblob->SessionKey.Length);
+
+		if (blob_len < (u64)sess_key_off + sess_key_len)
+			return -EINVAL;
+
+		ctx_arc4 = kmalloc(sizeof(*ctx_arc4), GFP_KERNEL);
+		if (!ctx_arc4)
+			return -ENOMEM;
+
+		cifs_arc4_setkey(ctx_arc4, sess->sess_key,
+				 SMB2_NTLMV2_SESSKEY_SIZE);
+		cifs_arc4_crypt(ctx_arc4, sess->sess_key,
+				(char *)authblob + sess_key_off, sess_key_len);
+		kfree_sensitive(ctx_arc4);
+	}
+
 	return ret;
 }
 
@@ -408,6 +432,9 @@ ksmbd_build_ntlmssp_challenge_blob(struct challenge_message *chgblob,
 	    (cflags & NTLMSSP_NEGOTIATE_EXTENDED_SEC))
 		flags |= NTLMSSP_NEGOTIATE_EXTENDED_SEC;
 
+	if (cflags & NTLMSSP_NEGOTIATE_KEY_XCH)
+		flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
+
 	chgblob->NegotiateFlags = cpu_to_le32(flags);
 	len = strlen(ksmbd_netbios_name());
 	name = kmalloc(2 + UNICODE_LEN(len), GFP_KERNEL);

fs/ksmbd/smb2pdu.c

@@ -2688,7 +2688,7 @@ int smb2_open(struct ksmbd_work *work)
 					(struct create_posix *)context;
 				if (le16_to_cpu(context->DataOffset) +
 				    le32_to_cpu(context->DataLength) <
-				    sizeof(struct create_posix)) {
+				    sizeof(struct create_posix) - 4) {
 					rc = -EINVAL;
 					goto err_out1;
 				}
@@ -3422,9 +3422,9 @@ static int smb2_populate_readdir_entry(struct ksmbd_conn *conn, int info_level,
 		goto free_conv_name;
 	}
 
-	struct_sz = readdir_info_level_struct_sz(info_level);
+	struct_sz = readdir_info_level_struct_sz(info_level) - 1 + conv_len;
-	next_entry_offset = ALIGN(struct_sz - 1 + conv_len,
+	next_entry_offset = ALIGN(struct_sz, KSMBD_DIR_INFO_ALIGNMENT);
-				  KSMBD_DIR_INFO_ALIGNMENT);
+	d_info->last_entry_off_align = next_entry_offset - struct_sz;
 
 	if (next_entry_offset > d_info->out_buf_len) {
 		d_info->out_buf_len = 0;
@@ -3976,6 +3976,7 @@ int smb2_query_dir(struct ksmbd_work *work)
 		((struct file_directory_info *)
 		((char *)rsp->Buffer + d_info.last_entry_offset))
 		->NextEntryOffset = 0;
+		d_info.data_count -= d_info.last_entry_off_align;
 
 		rsp->StructureSize = cpu_to_le16(9);
 		rsp->OutputBufferOffset = cpu_to_le16(72);
@@ -6126,13 +6127,26 @@ static int smb2_set_remote_key_for_rdma(struct ksmbd_work *work,
 					__le16 ChannelInfoOffset,
 					__le16 ChannelInfoLength)
 {
+	unsigned int i, ch_count;
+
 	if (work->conn->dialect == SMB30_PROT_ID &&
 	    Channel != SMB2_CHANNEL_RDMA_V1)
 		return -EINVAL;
 
-	if (ChannelInfoOffset == 0 ||
+	ch_count = le16_to_cpu(ChannelInfoLength) / sizeof(*desc);
-	    le16_to_cpu(ChannelInfoLength) < sizeof(*desc))
+	if (ksmbd_debug_types & KSMBD_DEBUG_RDMA) {
+		for (i = 0; i < ch_count; i++) {
+			pr_info("RDMA r/w request %#x: token %#x, length %#x\n",
+				i,
+				le32_to_cpu(desc[i].token),
+				le32_to_cpu(desc[i].length));
+		}
+	}
+	if (ch_count != 1) {
+		ksmbd_debug(RDMA, "RDMA multiple buffer descriptors %d are not supported yet\n",
+			    ch_count);
 		return -EINVAL;
+	}
 
 	work->need_invalidate_rkey =
 		(Channel == SMB2_CHANNEL_RDMA_V1_INVALIDATE);
@@ -6185,9 +6199,15 @@ int smb2_read(struct ksmbd_work *work)
 
 	if (req->Channel == SMB2_CHANNEL_RDMA_V1_INVALIDATE ||
 	    req->Channel == SMB2_CHANNEL_RDMA_V1) {
+		unsigned int ch_offset = le16_to_cpu(req->ReadChannelInfoOffset);
+
+		if (ch_offset < offsetof(struct smb2_read_req, Buffer)) {
+			err = -EINVAL;
+			goto out;
+		}
 		err = smb2_set_remote_key_for_rdma(work,
 						   (struct smb2_buffer_desc_v1 *)
-						   &req->Buffer[0],
+						   ((char *)req + ch_offset),
 						   req->Channel,
 						   req->ReadChannelInfoOffset,
 						   req->ReadChannelInfoLength);
@@ -6428,11 +6448,16 @@ int smb2_write(struct ksmbd_work *work)
 
 	if (req->Channel == SMB2_CHANNEL_RDMA_V1 ||
 	    req->Channel == SMB2_CHANNEL_RDMA_V1_INVALIDATE) {
-		if (req->Length != 0 || req->DataOffset != 0)
+		unsigned int ch_offset = le16_to_cpu(req->WriteChannelInfoOffset);
-			return -EINVAL;
+
+		if (req->Length != 0 || req->DataOffset != 0 ||
+		    ch_offset < offsetof(struct smb2_write_req, Buffer)) {
+			err = -EINVAL;
+			goto out;
+		}
 		err = smb2_set_remote_key_for_rdma(work,
 						   (struct smb2_buffer_desc_v1 *)
-						   &req->Buffer[0],
+						   ((char *)req + ch_offset),
 						   req->Channel,
 						   req->WriteChannelInfoOffset,
 						   req->WriteChannelInfoLength);

fs/ksmbd/smb_common.c

@@ -308,14 +308,17 @@ int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level,
 	for (i = 0; i < 2; i++) {
 		struct kstat kstat;
 		struct ksmbd_kstat ksmbd_kstat;
+		struct dentry *dentry;
 
 		if (!dir->dot_dotdot[i]) { /* fill dot entry info */
 			if (i == 0) {
 				d_info->name = ".";
 				d_info->name_len = 1;
+				dentry = dir->filp->f_path.dentry;
 			} else {
 				d_info->name = "..";
 				d_info->name_len = 2;
+				dentry = dir->filp->f_path.dentry->d_parent;
 			}
 
 			if (!match_pattern(d_info->name, d_info->name_len,
@@ -327,7 +330,7 @@ int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level,
 			ksmbd_kstat.kstat = &kstat;
 			ksmbd_vfs_fill_dentry_attrs(work,
 						    user_ns,
-						    dir->filp->f_path.dentry->d_parent,
+						    dentry,
 						    &ksmbd_kstat);
 			rc = fn(conn, info_level, d_info, &ksmbd_kstat);
 			if (rc)

fs/ksmbd/transport_rdma.c

@@ -80,7 +80,7 @@ static int smb_direct_max_fragmented_recv_size = 1024 * 1024;
 /*  The maximum single-message size which can be received */
 static int smb_direct_max_receive_size = 8192;
 
-static int smb_direct_max_read_write_size = 1048512;
+static int smb_direct_max_read_write_size = 524224;
 
 static int smb_direct_max_outstanding_rw_ops = 8;
 

fs/ksmbd/vfs.h

@@ -47,6 +47,7 @@ struct ksmbd_dir_info {
 	int		last_entry_offset;
 	bool		hide_dot_file;
 	int		flags;
+	int		last_entry_off_align;
 };
 
 struct ksmbd_readdir_data {