target: Fix SPC-2 RELEASE bug for multi-session iSCSI client setups

This patch addresses a bug in a special case for target core SPC-2 RELEASE
logic where the same physical client (eg: iSCSI InitiatorName) with
differing iSCSI session identifiers (ISID) is allowed to incorrectly release
the same client's SPC-2 reservation from the non reservation holding path.

Note this bug is specific to iscsi-target w/ SPC-2 reservations, and
with the default enforce_pr_isids=1 device attr setting in target-core
controls if a InitiatorName + different ISID reservations are handled
the same as a single iSCSI client entity.

Signed-off-by: Bernhard Kohl <bernhard.kohl@gmx.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 86f0c3b5d500..c3148b10b4b3 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -220,6 +220,9 @@ int target_scsi2_reservation_release(struct se_task *task)
         if (dev->dev_reserved_node_acl != sess->se_node_acl)
                 goto out_unlock;
 
+        if (dev->dev_res_bin_isid != sess->sess_bin_isid)
+                goto out_unlock;
+
         dev->dev_reserved_node_acl = NULL;
         dev->dev_flags &= ~DF_SPC2_RESERVATIONS;
         if (dev->dev_flags & DF_SPC2_RESERVATIONS_WITH_ISID) {