1 files changed, 38 insertions, 13 deletions

diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index cb4fd09f996e..3464470d3297 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -785,9 +785,9 @@ next_iface:
 			break;
 		}
 		/* Validate that Next doesn't point beyond the buffer */
-		if (next > bytes_left) {
-			cifs_dbg(VFS, "%s: invalid Next pointer %zu > %zd\n",
-				 __func__, next, bytes_left);
+		if (next < sizeof(*p) || next > bytes_left) {
+			cifs_dbg(VFS, "%s: invalid Next pointer %zu out of range [%zu, %zd]\n",
+				 __func__, next, sizeof(*p), bytes_left);
 			rc = -EINVAL;
 			goto out;
 		}
@@ -1053,8 +1053,9 @@ move_smb2_ea_to_cifs(char *dst, size_t dst_size,
 	char *name, *value;
 	size_t buf_size = dst_size;
 	size_t name_len, value_len, user_name_len;
+	u32 next_off;
 
-	while (src_size > 0) {
+	while (src_size >= sizeof(*src)) {
 		name_len = (size_t)src->ea_name_length;
 		value_len = (size_t)le16_to_cpu(src->ea_value_length);
 
@@ -1110,14 +1111,22 @@ move_smb2_ea_to_cifs(char *dst, size_t dst_size,
 		if (!src->next_entry_offset)
 			break;
 
-		if (src_size < le32_to_cpu(src->next_entry_offset)) {
-			/* stop before overrun buffer */
-			rc = -ERANGE;
-			break;
+		next_off = le32_to_cpu(src->next_entry_offset);
+		if (next_off < sizeof(*src) || src_size < next_off) {
+			cifs_dbg(FYI, "EA next_entry_offset %u out of range [%zu, %zu]\n",
+				 next_off, sizeof(*src), src_size);
+			rc = smb_EIO2(smb_eio_trace_ea_next_offset,
+				      next_off, src_size);
+			goto out;
+		}
+		src_size -= next_off;
+		src = (void *)((char *)src + next_off);
+		if (src_size > 0 && src_size < sizeof(*src)) {
+			cifs_dbg(FYI, "EA next_entry_offset %u left truncated entry (%zu bytes)\n",
+				 next_off, src_size);
+			rc = smb_EIO2(smb_eio_trace_ea_next_offset, next_off, src_size);
+			goto out;
 		}
-		src_size -= le32_to_cpu(src->next_entry_offset);
-		src = (void *)((char *)src +
-			       le32_to_cpu(src->next_entry_offset));
 	}
 
 	/* didn't find the named attribute */
@@ -2454,8 +2463,14 @@ smb3_enum_snapshots(const unsigned int xid, struct cifs_tcon *tcon,
 		 * and retry the ioctl again with larger array size sufficient
 		 * to hold all of the snapshot GMT tokens on the second try.
 		 */
-		if (snapshot_in.snapshot_array_size < GMT_TOKEN_SIZE)
+		if (snapshot_in.snapshot_array_size < GMT_TOKEN_SIZE) {
+			if (ret_data_len < sizeof(struct smb_snapshot_array)) {
+				rc = -EIO;
+				kfree(retbuf);
+				return rc;
+			}
 			ret_data_len = sizeof(struct smb_snapshot_array);
+		}
 
 		/*
 		 * We return struct SRV_SNAPSHOT_ARRAY, followed by
@@ -5365,11 +5380,13 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
 	length = decrypt_raw_data(server, buf, buf_size, NULL, false);
 	if (length)
 		return length;
+	pdu_length = buf_size;
 
 	next_is_large = server->large_buf;
 one_more:
 	shdr = (struct smb2_hdr *)buf;
 	next_cmd = le32_to_cpu(shdr->NextCommand);
+	server->total_read = next_cmd ? next_cmd : pdu_length;
 
 	if (*num_mids >= MAX_COMPOUND) {
 		cifs_server_dbg(VFS, "too many PDUs in compound\n");
@@ -5377,8 +5394,15 @@ one_more:
 	}
 
 	if (next_cmd) {
-		if (WARN_ON_ONCE(next_cmd > pdu_length))
+		if (next_cmd < MID_HEADER_SIZE(server) ||
+		    next_cmd > pdu_length ||
+		    pdu_length - next_cmd < MID_HEADER_SIZE(server)) {
+			unsigned int max_next = pdu_length > (unsigned int)MID_HEADER_SIZE(server) ?
+					pdu_length - (unsigned int)MID_HEADER_SIZE(server) : 0;
+			cifs_server_dbg(VFS, "invalid NextCommand offset %u out of range [%zu, %u]\n",
+					next_cmd, MID_HEADER_SIZE(server), max_next);
 			return -1;
+		}
 		if (next_is_large)
 			next_buffer = (char *)cifs_buf_get();
 		else
@@ -5414,6 +5438,7 @@ one_more:
 			server->bigbuf = buf = next_buffer;
 		else
 			server->smallbuf = buf = next_buffer;
+		next_buffer = NULL;
 		goto one_more;
 	} else if (ret != 0) {
 		/*