From: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Fri, 13 Feb 2015 22:27:40 +0000 (+0000)
Subject: target: Check for LBA + sectors wrap-around in sbc_parse_cdb
X-Git-Tag: firefly_0821_release~3679^2~729
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=84ba11a6ee549b2727a3b83d3c1b455df1c7ebcd;p=firefly-linux-kernel-4.4.55.git

target: Check for LBA + sectors wrap-around in sbc_parse_cdb

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>
---

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 92e6c510e5d0..70b0d265c37d 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -562,7 +562,8 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 		unsigned long long end_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);