From: HyeongJun An Date: Thu, 16 Jul 2026 06:58:48 +0000 (+0900) Subject: scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer X-Git-Tag: v7.2-rc6~7^2~10 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=c1dea15f819cded9b3faf58f8bec72323568b6e6;p=thirdparty%2Flinux.git scsi: libiscsi_tcp: Bound SCSI Response data segment to the connection buffer iscsi_tcp_hdr_dissect() receives the data segment of several PDU types into the fixed-size conn->data buffer, which is allocated for ISCSI_DEF_MAX_RECV_SEG_LEN (8192) bytes. For the LOGIN_RSP, TEXT_RSP, REJECT and ASYNC_EVENT opcodes the dissect path already rejects a PDU whose DataSegmentLength exceeds that buffer. The SCSI Command Response (ISCSI_OP_SCSI_CMD_RSP) path also copies its data segment (sense/response data) into conn->data via iscsi_tcp_data_recv_prep(), but it does so without the same check. The only upstream bound on in.datalen is conn->max_recv_dlength, the initiator's advertised MaxRecvDataSegmentLength, which is commonly negotiated well above 8192 (open-iscsi defaults to 262144). A target that returns a SCSI Response with a DataSegmentLength between 8193 and max_recv_dlength therefore overflows the 8192-byte conn->data buffer. Once the same bound applies, ISCSI_OP_SCSI_CMD_RSP is handled exactly like those responses: bound the data segment, receive it into conn->data when present, and otherwise complete the PDU with no data. Fold the opcode into that case group rather than duplicating the check. Fixes: a081c13e39b5 ("[SCSI] iscsi_tcp: split module into lib and lld") Suggested-by: Chris Leech Assisted-by: Claude:claude-opus-4-8 Signed-off-by: HyeongJun An Acked-by: Chris Leech Link: https://patch.msgid.link/20260716065848.1653431-1-sammiee5311@gmail.com Signed-off-by: Martin K. Petersen --- diff --git a/drivers/scsi/libiscsi_tcp.c b/drivers/scsi/libiscsi_tcp.c index e90805ba868f..7223bb18b048 100644 --- a/drivers/scsi/libiscsi_tcp.c +++ b/drivers/scsi/libiscsi_tcp.c @@ -752,13 +752,6 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr) rc = __iscsi_complete_pdu(conn, hdr, NULL, 0); spin_unlock(&conn->session->back_lock); break; - case ISCSI_OP_SCSI_CMD_RSP: - if (tcp_conn->in.datalen) { - iscsi_tcp_data_recv_prep(tcp_conn); - return 0; - } - rc = iscsi_complete_pdu(conn, hdr, NULL, 0); - break; case ISCSI_OP_R2T: if (ahslen) { rc = ISCSI_ERR_AHSLEN; @@ -766,6 +759,7 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr) } rc = iscsi_tcp_r2t_rsp(conn, hdr); break; + case ISCSI_OP_SCSI_CMD_RSP: case ISCSI_OP_LOGIN_RSP: case ISCSI_OP_TEXT_RSP: case ISCSI_OP_REJECT: