target: Add missing WRITE_SAME end-of-device sanity check

This patch adds a check to sbc_setup_write_same() to verify
the incoming WRITE_SAME LBA + number of blocks does not exceed
past the end-of-device.

Also check for potential LBA wrap-around as well.

Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org # 3.8+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 11bea1952435a397172ce69804a1088567bde03f..b26b52f441a192f96699263fbe6e040f069357bf 100644 (file)
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -251,6 +251,8 @@ static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 static sense_reason_t
 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
 {
+       struct se_device *dev = cmd->se_dev;
+       sector_t end_lba = dev->transport->get_blocks(dev) + 1;
        unsigned int sectors = sbc_get_write_same_sectors(cmd);
 
        if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
@@ -264,6 +266,16 @@ sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *o
                        sectors, cmd->se_dev->dev_attrib.max_write_same_len);
                return TCM_INVALID_CDB_FIELD;
        }
+       /*
+        * Sanity check for LBA wrap and request past end of device.
+        */
+       if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
+           ((cmd->t_task_lba + sectors) > end_lba)) {
+               pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
+                      (unsigned long long)end_lba, cmd->t_task_lba, sectors);
+               return TCM_ADDRESS_OUT_OF_RANGE;
+       }
+
        /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
        if (flags[0] & 0x10) {
                pr_warn("WRITE SAME with ANCHOR not supported\n");