[PATCH 3.19 056/177] target: Add missing WRITE_SAME end-of-device sanity check

Greg Kroah-Hartman
2015-03-16T14:14:07Z

From: Nicholas Bellinger <nab@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.vanassche@sandisk.com>
Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/target/target_core_sbc.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -251,6 +251,8 @@ static inline unsigned long long transpo
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,
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");