From d657700ccac71da19a4d1a591fafcd598ce0dd6e Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Wed, 2 Mar 2022 00:35:48 -0500 Subject: scsi: core: Do not truncate INQUIRY data on modern devices Low-level device drivers have had the ability to limit the size of an INQUIRY for many years. This made sense for a wide variety of legacy devices. However, we are unnecessarily truncating the INQUIRY response for many modern devices. This prevents us from consulting fields beyond the first 36 bytes. If a device reports that it supports a larger INQUIRY response, and the device also reports that it implements SPC-4 or newer, allow the larger INQUIRY to proceed. Link: https://lore.kernel.org/r/20220302053559.32147-4-martin.petersen@oracle.com Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Signed-off-by: Martin K. Petersen --- drivers/scsi/scsi_scan.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'drivers/scsi/scsi_scan.c') diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 2ef78083f1ef..91ac901a6682 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -733,7 +733,17 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, if (pass == 1) { if (BLIST_INQUIRY_36 & *bflags) next_inquiry_len = 36; - else if (sdev->inquiry_len) + /* + * LLD specified a maximum sdev->inquiry_len + * but device claims it has more data. Capping + * the length only makes sense for legacy + * devices. If a device supports SPC-4 (2014) + * or newer, assume that it is safe to ask for + * as much as the device says it supports. + */ + else if (sdev->inquiry_len && + response_len > sdev->inquiry_len && + (inq_result[2] & 0x7) < 6) /* SPC-4 */ next_inquiry_len = sdev->inquiry_len; else next_inquiry_len = response_len; -- cgit