[PATCH 101/139] target: Add missing mapped_lun bounds checking during make_mappedlun setup

[Luis Henriques]

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

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

From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>

commit fbbf8555a986ed31e54f006b6cc637ea4ff1425b upstream.

This patch adds missing bounds checking for the configfs provided
mapped_lun value during target_fabric_make_mappedlun() setup ahead
of se_lun_acl initialization.

This addresses a potential OOPs when using a mapped_lun value that
exceeds the hardcoded TRANSPORT_MAX_LUNS_PER_TPG-1 value within
se_node_acl->device_list[].

Reported-by: Jan Engelhardt <jengelh@xxxxxxx>
Cc: Jan Engelhardt <jengelh@xxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
 drivers/target/target_core_fabric_configfs.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/target/target_core_fabric_configfs.c b/drivers/target/target_core_fabric_configfs.c
index 040751b..c42143b 100644
--- a/drivers/target/target_core_fabric_configfs.c
+++ b/drivers/target/target_core_fabric_configfs.c
@@ -350,6 +350,14 @@ static struct config_group *target_fabric_make_mappedlun(
 		ret = -EINVAL;
 		goto out;
 	}
+	if (mapped_lun > (TRANSPORT_MAX_LUNS_PER_TPG-1)) {
+		pr_err("Mapped LUN: %lu exceeds TRANSPORT_MAX_LUNS_PER_TPG"
+			"-1: %u for Target Portal Group: %u\n", mapped_lun,
+			TRANSPORT_MAX_LUNS_PER_TPG-1,
+			se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg));
+		ret = -EINVAL;
+		goto out;
+	}
 
 	lacl = core_dev_init_initiator_node_lun_acl(se_tpg, se_nacl,
 			mapped_lun, &ret);
-- 
1.8.1.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/