[PATCH 4.4 205/210] scsi_common: do not clobber fixed sense information

From: Greg Kroah-Hartman
Date: Sun Apr 10 2016 - 15:44:12 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Hannes Reinecke <hare@xxxxxxx>

commit ba08311647892cc7912de74525fd78416caf544a upstream.

For fixed sense the information field is 32 bits, to we need to truncate
the information field to avoid clobbering the sense code.

Fixes: a1524f226a02 ("libata-eh: Set 'information' field for autosense")
Signed-off-by: Hannes Reinecke <hare@xxxxxxxx>
Reviewed-by: Lee Duncan <lduncan@xxxxxxxx>
Reviewed-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Reviewed-by: Ewan D. Milne <emilne@xxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/scsi/scsi_common.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

--- a/drivers/scsi/scsi_common.c
+++ b/drivers/scsi/scsi_common.c
@@ -278,8 +278,16 @@ int scsi_set_sense_information(u8 *buf,
ucp[3] = 0;
put_unaligned_be64(info, &ucp[4]);
} else if ((buf[0] & 0x7f) == 0x70) {
- buf[0] |= 0x80;
- put_unaligned_be64(info, &buf[3]);
+ /*
+ * Only set the 'VALID' bit if we can represent the value
+ * correctly; otherwise just fill out the lower bytes and
+ * clear the 'VALID' flag.
+ */
+ if (info <= 0xffffffffUL)
+ buf[0] |= 0x80;
+ else
+ buf[0] &= 0x7f;
+ put_unaligned_be32((u32)info, &buf[3]);
}

return 0;