1 files changed, 14 insertions, 4 deletions

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 148e24cc3222..aa1b1e0e9d22 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -700,12 +700,22 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
          * scanning run at their own risk, or supply a user level program
          * that can correctly scan.
          */
-        sdev->inquiry = kmalloc(sdev->inquiry_len, GFP_ATOMIC);
-        if (sdev->inquiry == NULL) {
+
+        /*
+         * Copy at least 36 bytes of INQUIRY data, so that we don't
+         * dereference unallocated memory when accessing the Vendor,
+         * Product, and Revision strings.  Badly behaved devices may set
+         * the INQUIRY Additional Length byte to a small value, indicating
+         * these strings are invalid, but often they contain plausible data
+         * nonetheless.  It doesn't matter if the device sent < 36 bytes
+         * total, since scsi_probe_lun() initializes inq_result with 0s.
+         */
+        sdev->inquiry = kmemdup(inq_result,
+                                max_t(size_t, sdev->inquiry_len, 36),
+                                GFP_ATOMIC);
+        if (sdev->inquiry == NULL)
                 return SCSI_SCAN_NO_RESPONSE;
-        }
 
-        memcpy(sdev->inquiry, inq_result, sdev->inquiry_len);
         sdev->vendor = (char *) (sdev->inquiry + 8);
         sdev->model = (char *) (sdev->inquiry + 16);
         sdev->rev = (char *) (sdev->inquiry + 32);