[PATCH 15/33] scsi: qla2xxx: Bound rsp_info_len to avoid OOB sense-data read

In qla2x00_status_entry(), the FWI2 status path advances sense_data and
shrinks par_sense_len by rsp_info_len:

	if (IS_FWI2_CAPABLE(ha)) {
		sense_data += rsp_info_len;
		par_sense_len -= rsp_info_len;
	}

rsp_info_len is a 32-bit value taken directly from the target's FCP
response (sf.rsp_data_len), while par_sense_len is the IOCB data area
size (28 bytes for 24xx, 60 bytes for 29xx). A hostile or buggy target
reporting an rsp_info_len larger than par_sense_len makes the unsigned
subtraction underflow to a huge value and advances sense_data out of
bounds.

The underflowed par_sense_len then defeats the cap in
qla2x00_handle_sense():

	if (sense_len > par_sense_len)
		sense_len = par_sense_len;
	memcpy(cp->sense_buffer, sense_data, sense_len);

so the memcpy reads up to SCSI_SENSE_BUFFERSIZE bytes from the
out-of-bounds sense_data pointer, leaking adjacent response-ring/heap
memory into the command's sense buffer.

Clamp rsp_info_len to par_sense_len before the subtraction so
par_sense_len can never underflow and sense_data stays within the IOCB
data area. The fix sits before the comp_status switch, covering both
qla2x00_handle_sense() call sites.

Fixes: 5544213be7b4 ("[SCSI] qla2xxx: Correct extended sense-data handling.")
Cc: [email protected]
Reported-by: Sashiko <[email protected]>
Signed-off-by: Nilesh Javali <[email protected]>
---
 drivers/scsi/qla2xxx/qla_isr.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index d9019f2b059c..02f88a79964a 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -3598,6 +3598,18 @@ qla2x00_status_entry(scsi_qla_host_t *vha, struct rsp_que *rsp, void *pkt)
 	if (scsi_status & SS_RESPONSE_INFO_LEN_VALID) {
 		/* Sense data lies beyond any FCP RESPONSE data. */
 		if (IS_FWI2_CAPABLE(ha)) {
+			/*
+			 * A hostile or buggy target may report an
+			 * rsp_info_len larger than the IOCB data area.
+			 * Clamp it so the par_sense_len subtraction cannot
+			 * underflow and walk sense_data out of bounds.
+			 */
+			if (rsp_info_len > par_sense_len) {
+				ql_log(ql_log_warn, fcport->vha, 0x3107,
+				       "Truncating bogus rsp_info_len 0x%x to 0x%x.\n",
+				       rsp_info_len, par_sense_len);
+				rsp_info_len = par_sense_len;
+			}
 			sense_data += rsp_info_len;
 			par_sense_len -= rsp_info_len;
 		}
-- 
2.47.3