From: Bart Van Assche bvanassche@acm.org
[ Upstream commit 63f7479439c95bcd49b7dd4af809862c316c71a3 ]
The rcu_dereference(deve->se_lun) expression occurs twice in the LUN lookup functions. Since these expressions are not serialized against deve->se_lun assignments each of these expressions may yield a different result. Avoid that the wrong LUN pointer is stored in se_cmd by reading deve->se_lun only once.
Cc: Mike Christie mchristi@redhat.com Cc: Christoph Hellwig hch@lst.de Cc: Hannes Reinecke hare@suse.com Cc: Nicholas Bellinger nab@linux-iscsi.org Fixes: 29a05deebf6c ("target: Convert se_node_acl->device_list[] to RCU hlist") # v4.10 Signed-off-by: Bart Van Assche bvanassche@acm.org Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/target/target_core_device.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index 92b52d2314b53..cebef8e5a43d1 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -85,7 +85,7 @@ transport_lookup_cmd_lun(struct se_cmd *se_cmd, u64 unpacked_lun) goto out_unlock; }
- se_cmd->se_lun = rcu_dereference(deve->se_lun); + se_cmd->se_lun = se_lun; se_cmd->pr_res_key = deve->pr_res_key; se_cmd->orig_fe_lun = unpacked_lun; se_cmd->se_cmd_flags |= SCF_SE_LUN_CMD; @@ -176,7 +176,7 @@ int transport_lookup_tmr_lun(struct se_cmd *se_cmd, u64 unpacked_lun) goto out_unlock; }
- se_cmd->se_lun = rcu_dereference(deve->se_lun); + se_cmd->se_lun = se_lun; se_cmd->pr_res_key = deve->pr_res_key; se_cmd->orig_fe_lun = unpacked_lun; se_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;