3.13.11-ckt18 -stable review patch.  If anyone has any objections, please let 
me know.

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

From: Nicholas Bellinger <n...@linux-iscsi.org>

commit 8e575c50a171f2579e367a7f778f86477dfdaf49 upstream.

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.vanass...@sandisk.com>
Cc: Martin Petersen <martin.peter...@oracle.com>
Cc: Christoph Hellwig <h...@lst.de>
Signed-off-by: Nicholas Bellinger <n...@linux-iscsi.org>
Signed-off-by: Kamal Mostafa <ka...@canonical.com>
---
 drivers/target/target_core_sbc.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 6aae89d..3039bc4 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -260,6 +260,8 @@ 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)) {
@@ -273,6 +275,16 @@ 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");
-- 
1.9.1

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