3 files changed, 26 insertions, 3 deletions

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 828697015759..8cdea25f1377 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1568,9 +1568,11 @@ iscsit_get_dataout(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
 {
         struct kvec *iov;
         u32 checksum, iov_count = 0, padding = 0, rx_got = 0, rx_size = 0;
-        u32 payload_length = ntoh24(hdr->dlength);
+        u32 payload_length;
         int iov_ret, data_crc_failed = 0;
 
+        payload_length = min_t(u32, cmd->se_cmd.data_length,
+                               ntoh24(hdr->dlength));
         rx_size += payload_length;
         iov = &cmd->iov_data[0];
 
@@ -2575,14 +2577,33 @@ static int iscsit_handle_immediate_data(
         u32 checksum, iov_count = 0, padding = 0;
         struct iscsi_conn *conn = cmd->conn;
         struct kvec *iov;
+        void *overflow_buf = NULL;
 
-        iov_ret = iscsit_map_iovec(cmd, cmd->iov_data, cmd->write_data_done, length);
+        BUG_ON(cmd->write_data_done > cmd->se_cmd.data_length);
+        rx_size = min(cmd->se_cmd.data_length - cmd->write_data_done, length);
+        iov_ret = iscsit_map_iovec(cmd, cmd->iov_data, cmd->write_data_done,
+                                   rx_size);
         if (iov_ret < 0)
                 return IMMEDIATE_DATA_CANNOT_RECOVER;
 
-        rx_size = length;
         iov_count = iov_ret;
         iov = &cmd->iov_data[0];
+        if (rx_size < length) {
+                /*
+                 * Special case: length of immediate data exceeds the data
+                 * buffer size derived from the CDB.
+                 */
+                overflow_buf = kmalloc(length - rx_size, GFP_KERNEL);
+                if (!overflow_buf) {
+                        iscsit_unmap_iovec(cmd);
+                        return IMMEDIATE_DATA_CANNOT_RECOVER;
+                }
+                cmd->overflow_buf = overflow_buf;
+                iov[iov_count].iov_base = overflow_buf;
+                iov[iov_count].iov_len = length - rx_size;
+                iov_count++;
+                rx_size = length;
+        }
 
         padding = ((-length) & 3);
         if (padding != 0) {
diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index 5b26bc23016a..fae85bfd790e 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -737,6 +737,7 @@ void iscsit_release_cmd(struct iscsi_cmd *cmd)
         kfree(cmd->pdu_list);
         kfree(cmd->seq_list);
         kfree(cmd->tmr_req);
+        kfree(cmd->overflow_buf);
         kfree(cmd->iov_data);
         kfree(cmd->text_in_ptr);
 
diff --git a/include/target/iscsi/iscsi_target_core.h b/include/target/iscsi/iscsi_target_core.h
index 24c398f4a68f..a49d37140a64 100644
--- a/include/target/iscsi/iscsi_target_core.h
+++ b/include/target/iscsi/iscsi_target_core.h
@@ -473,6 +473,7 @@ struct iscsi_cmd {
         struct timer_list       dataout_timer;
         /* Iovecs for SCSI data payload RX/TX w/ kernel level sockets */
         struct kvec             *iov_data;
+        void                    *overflow_buf;
         /* Iovecs for miscellaneous purposes */
 #define ISCSI_MISC_IOVECS                       5
         struct kvec             iov_misc[ISCSI_MISC_IOVECS];