1 files changed, 7 insertions, 10 deletions

diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index b3d8fd260374..9229bd9ad61b 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -784,7 +784,7 @@ static int spc_emulate_modesense(struct se_cmd *cmd)
         unsigned char *rbuf;
         int type = dev->transport->get_device_type(dev);
         int ten = (cmd->t_task_cdb[0] == MODE_SENSE_10);
-        int offset = ten ? 8 : 4;
+        u32 offset = ten ? 8 : 4;
         int length = 0;
         unsigned char buf[SE_MODE_PAGE_BUF];
 
@@ -817,6 +817,7 @@ static int spc_emulate_modesense(struct se_cmd *cmd)
                 offset -= 2;
                 buf[0] = (offset >> 8) & 0xff;
                 buf[1] = offset & 0xff;
+                offset += 2;
 
                 if ((cmd->se_lun->lun_access & TRANSPORT_LUNFLAGS_READ_ONLY) ||
                     (cmd->se_deve &&
@@ -826,13 +827,10 @@ static int spc_emulate_modesense(struct se_cmd *cmd)
                 if ((dev->se_sub_dev->se_dev_attrib.emulate_write_cache > 0) &&
                     (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0))
                         spc_modesense_dpofua(&buf[3], type);
-
-                if ((offset + 2) > cmd->data_length)
-                        offset = cmd->data_length;
-
         } else {
                 offset -= 1;
                 buf[0] = offset & 0xff;
+                offset += 1;
 
                 if ((cmd->se_lun->lun_access & TRANSPORT_LUNFLAGS_READ_ONLY) ||
                     (cmd->se_deve &&
@@ -842,14 +840,13 @@ static int spc_emulate_modesense(struct se_cmd *cmd)
                 if ((dev->se_sub_dev->se_dev_attrib.emulate_write_cache > 0) &&
                     (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0))
                         spc_modesense_dpofua(&buf[2], type);
-
-                if ((offset + 1) > cmd->data_length)
-                        offset = cmd->data_length;
         }
 
         rbuf = transport_kmap_data_sg(cmd);
-        memcpy(rbuf, buf, offset);
-        transport_kunmap_data_sg(cmd);
+        if (rbuf) {
+                memcpy(rbuf, buf, min(offset, cmd->data_length));
+                transport_kunmap_data_sg(cmd);
+        }
 
         target_complete_cmd(cmd, GOOD);
         return 0;