[PATCH 3.19 057/177] target: Check for LBA + sectors wrap-around in sbc_parse_cdb

Greg Kroah-Hartman
2015-03-16T14:14:43Z

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

commit aa179935edea9a64dec4b757090c8106a3907ffa upstream.

This patch adds a check to sbc_parse_cdb() in order to detect when
an LBA + sector vs. end-of-device calculation wraps when the LBA is
sufficently large enough (eg: 0xFFFFFFFFFFFFFFFF).

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 | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -967,7 +967,8 @@ sbc_parse_cdb(struct se_cmd *cmd, struct
unsigned long long end_lba;
check_lba:
end_lba = dev->transport->get_blocks(dev) + 1;
- if (cmd->t_task_lba + sectors > end_lba) {
+ if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
+ ((cmd->t_task_lba + sectors) > end_lba)) {
pr_err("cmd exceeds last lba %llu "
"(lba %llu, sectors %u)\n",
end_lba, cmd->t_task_lba, sectors);