1 files changed, 79 insertions, 46 deletions

diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index 20634fc6d4f0..4f971c1061f0 100644
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -411,8 +411,7 @@ skip_sess_setup:
 	}
 
 	if (smb2_command != SMB2_INTERNAL_CMD)
-		if (mod_delayed_work(cifsiod_wq, &server->reconnect, 0))
-			cifs_put_tcp_session(server, false);
+		mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 
 	atomic_inc(&tconInfoReconnectCount);
 out:
@@ -471,10 +470,15 @@ static int __smb2_plain_req_init(__le16 smb2_command, struct cifs_tcon *tcon,
 				 void **request_buf, unsigned int *total_len)
 {
 	/* BB eventually switch this to SMB2 specific small buf size */
-	if (smb2_command == SMB2_SET_INFO)
+	switch (smb2_command) {
+	case SMB2_SET_INFO:
+	case SMB2_QUERY_INFO:
 		*request_buf = cifs_buf_get();
-	else
+		break;
+	default:
 		*request_buf = cifs_small_buf_get();
+		break;
+	}
 	if (*request_buf == NULL) {
 		/* BB should we add a retry in here if not a writepage? */
 		return -ENOMEM;
@@ -2236,17 +2240,18 @@ parse_posix_ctxt(struct create_context *cc, struct smb2_file_all_info *info,
 		 posix->nlink, posix->mode, posix->reparse_tag);
 }
 
-void
-smb2_parse_contexts(struct TCP_Server_Info *server,
-		    struct smb2_create_rsp *rsp,
-		    unsigned int *epoch, char *lease_key, __u8 *oplock,
-		    struct smb2_file_all_info *buf,
-		    struct create_posix_rsp *posix)
+int smb2_parse_contexts(struct TCP_Server_Info *server,
+			struct kvec *rsp_iov,
+			unsigned int *epoch,
+			char *lease_key, __u8 *oplock,
+			struct smb2_file_all_info *buf,
+			struct create_posix_rsp *posix)
 {
-	char *data_offset;
+	struct smb2_create_rsp *rsp = rsp_iov->iov_base;
 	struct create_context *cc;
-	unsigned int next;
-	unsigned int remaining;
+	size_t rem, off, len;
+	size_t doff, dlen;
+	size_t noff, nlen;
 	char *name;
 	static const char smb3_create_tag_posix[] = {
 		0x93, 0xAD, 0x25, 0x50, 0x9C,
@@ -2255,45 +2260,63 @@ smb2_parse_contexts(struct TCP_Server_Info *server,
 	};
 
 	*oplock = 0;
-	data_offset = (char *)rsp + le32_to_cpu(rsp->CreateContextsOffset);
-	remaining = le32_to_cpu(rsp->CreateContextsLength);
-	cc = (struct create_context *)data_offset;
+
+	off = le32_to_cpu(rsp->CreateContextsOffset);
+	rem = le32_to_cpu(rsp->CreateContextsLength);
+	if (check_add_overflow(off, rem, &len) || len > rsp_iov->iov_len)
+		return -EINVAL;
+	cc = (struct create_context *)((u8 *)rsp + off);
 
 	/* Initialize inode number to 0 in case no valid data in qfid context */
 	if (buf)
 		buf->IndexNumber = 0;
 
-	while (remaining >= sizeof(struct create_context)) {
-		name = le16_to_cpu(cc->NameOffset) + (char *)cc;
-		if (le16_to_cpu(cc->NameLength) == 4 &&
-		    strncmp(name, SMB2_CREATE_REQUEST_LEASE, 4) == 0)
-			*oplock = server->ops->parse_lease_buf(cc, epoch,
-							   lease_key);
-		else if (buf && (le16_to_cpu(cc->NameLength) == 4) &&
-		    strncmp(name, SMB2_CREATE_QUERY_ON_DISK_ID, 4) == 0)
-			parse_query_id_ctxt(cc, buf);
-		else if ((le16_to_cpu(cc->NameLength) == 16)) {
-			if (posix &&
-			    memcmp(name, smb3_create_tag_posix, 16) == 0)
+	while (rem >= sizeof(*cc)) {
+		doff = le16_to_cpu(cc->DataOffset);
+		dlen = le32_to_cpu(cc->DataLength);
+		if (check_add_overflow(doff, dlen, &len) || len > rem)
+			return -EINVAL;
+
+		noff = le16_to_cpu(cc->NameOffset);
+		nlen = le16_to_cpu(cc->NameLength);
+		if (noff + nlen >= doff)
+			return -EINVAL;
+
+		name = (char *)cc + noff;
+		switch (nlen) {
+		case 4:
+			if (!strncmp(name, SMB2_CREATE_REQUEST_LEASE, 4)) {
+				*oplock = server->ops->parse_lease_buf(cc, epoch,
+								       lease_key);
+			} else if (buf &&
+				   !strncmp(name, SMB2_CREATE_QUERY_ON_DISK_ID, 4)) {
+				parse_query_id_ctxt(cc, buf);
+			}
+			break;
+		case 16:
+			if (posix && !memcmp(name, smb3_create_tag_posix, 16))
 				parse_posix_ctxt(cc, buf, posix);
+			break;
+		default:
+			cifs_dbg(FYI, "%s: unhandled context (nlen=%zu dlen=%zu)\n",
+				 __func__, nlen, dlen);
+			if (IS_ENABLED(CONFIG_CIFS_DEBUG2))
+				cifs_dump_mem("context data: ", cc, dlen);
+			break;
 		}
-		/* else {
-			cifs_dbg(FYI, "Context not matched with len %d\n",
-				le16_to_cpu(cc->NameLength));
-			cifs_dump_mem("Cctxt name: ", name, 4);
-		} */
-
-		next = le32_to_cpu(cc->Next);
-		if (!next)
+
+		off = le32_to_cpu(cc->Next);
+		if (!off)
 			break;
-		remaining -= next;
-		cc = (struct create_context *)((char *)cc + next);
+		if (check_sub_overflow(rem, off, &rem))
+			return -EINVAL;
+		cc = (struct create_context *)((u8 *)cc + off);
 	}
 
 	if (rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE)
 		*oplock = rsp->OplockLevel;
 
-	return;
+	return 0;
 }
 
 static int
@@ -3124,8 +3147,8 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
 	}
 
 
-	smb2_parse_contexts(server, rsp, &oparms->fid->epoch,
-			    oparms->fid->lease_key, oplock, buf, posix);
+	rc = smb2_parse_contexts(server, &rsp_iov, &oparms->fid->epoch,
+				 oparms->fid->lease_key, oplock, buf, posix);
 creat_exit:
 	SMB2_open_free(&rqst);
 	free_rsp_buf(resp_buftype, rsp);
@@ -3568,8 +3591,13 @@ SMB2_query_info_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server,
 	struct smb2_query_info_req *req;
 	struct kvec *iov = rqst->rq_iov;
 	unsigned int total_len;
+	size_t len;
 	int rc;
 
+	if (unlikely(check_add_overflow(input_len, sizeof(*req), &len) ||
+		     len > CIFSMaxBufSize))
+		return -EINVAL;
+
 	rc = smb2_plain_req_init(SMB2_QUERY_INFO, tcon, server,
 				 (void **) &req, &total_len);
 	if (rc)
@@ -3591,7 +3619,7 @@ SMB2_query_info_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server,
 
 	iov[0].iov_base = (char *)req;
 	/* 1 for Buffer */
-	iov[0].iov_len = total_len - 1 + input_len;
+	iov[0].iov_len = len;
 	return 0;
 }
 
@@ -3599,7 +3627,7 @@ void
 SMB2_query_info_free(struct smb_rqst *rqst)
 {
 	if (rqst && rqst->rq_iov)
-		cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
+		cifs_buf_release(rqst->rq_iov[0].iov_base); /* request */
 }
 
 static int
@@ -5474,6 +5502,11 @@ build_qfs_info_req(struct kvec *iov, struct cifs_tcon *tcon,
 	return 0;
 }
 
+static inline void free_qfs_info_req(struct kvec *iov)
+{
+	cifs_buf_release(iov->iov_base);
+}
+
 int
 SMB311_posix_qfs_info(const unsigned int xid, struct cifs_tcon *tcon,
 	      u64 persistent_fid, u64 volatile_fid, struct kstatfs *fsdata)
@@ -5505,7 +5538,7 @@ SMB311_posix_qfs_info(const unsigned int xid, struct cifs_tcon *tcon,
 
 	rc = cifs_send_recv(xid, ses, server,
 			    &rqst, &resp_buftype, flags, &rsp_iov);
-	cifs_small_buf_release(iov.iov_base);
+	free_qfs_info_req(&iov);
 	if (rc) {
 		cifs_stats_fail_inc(tcon, SMB2_QUERY_INFO_HE);
 		goto posix_qfsinf_exit;
@@ -5556,7 +5589,7 @@ SMB2_QFS_info(const unsigned int xid, struct cifs_tcon *tcon,
 
 	rc = cifs_send_recv(xid, ses, server,
 			    &rqst, &resp_buftype, flags, &rsp_iov);
-	cifs_small_buf_release(iov.iov_base);
+	free_qfs_info_req(&iov);
 	if (rc) {
 		cifs_stats_fail_inc(tcon, SMB2_QUERY_INFO_HE);
 		goto qfsinf_exit;
@@ -5623,7 +5656,7 @@ SMB2_QFS_attr(const unsigned int xid, struct cifs_tcon *tcon,
 
 	rc = cifs_send_recv(xid, ses, server,
 			    &rqst, &resp_buftype, flags, &rsp_iov);
-	cifs_small_buf_release(iov.iov_base);
+	free_qfs_info_req(&iov);
 	if (rc) {
 		cifs_stats_fail_inc(tcon, SMB2_QUERY_INFO_HE);
 		goto qfsattr_exit;