From: Dmitry Bogdanov <d.bogdanov@xxxxxxxxx> Commands from recovery entries are freed after its session has been closed. That leads to use-after-free at command free or NPE with such call trace: Time2Retain timer expired for SID: 1, cleaning up iSCSI session. BUG: kernel NULL pointer dereference, address: 0000000000000140 RIP: 0010:sbitmap_queue_clear+0x3a/0xa0 Call Trace: target_release_cmd_kref+0xd1/0x1f0 [target_core_mod] transport_generic_free_cmd+0xd1/0x180 [target_core_mod] iscsit_free_cmd+0x53/0xd0 [iscsi_target_mod] iscsit_free_connection_recovery_entries+0x29d/0x320 [iscsi_target_mod] iscsit_close_session+0x13a/0x140 [iscsi_target_mod] iscsit_check_post_dataout+0x440/0x440 [iscsi_target_mod] call_timer_fn+0x24/0x140 Move cleanup of recovery enrties to before session freeing. Reported-by: Forza <forza@xxxxxxxxxxxx> Signed-off-by: Dmitry Bogdanov <d.bogdanov@xxxxxxxxx> Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx> --- drivers/target/iscsi/iscsi_target.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index a57527beb340..eac5af87ccd8 100644 --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -4547,6 +4547,9 @@ int iscsit_close_session(struct iscsit_session *sess, bool can_sleep) iscsit_stop_time2retain_timer(sess); spin_unlock_bh(&se_tpg->session_lock); + if (sess->sess_ops->ErrorRecoveryLevel == 2) + iscsit_free_connection_recovery_entries(sess); + /* * transport_deregister_session_configfs() will clear the * struct se_node_acl->nacl_sess pointer now as a iscsi_np process context @@ -4570,9 +4573,6 @@ int iscsit_close_session(struct iscsit_session *sess, bool can_sleep) transport_deregister_session(sess->se_sess); - if (sess->sess_ops->ErrorRecoveryLevel == 2) - iscsit_free_connection_recovery_entries(sess); - iscsit_free_all_ooo_cmdsns(sess); spin_lock_bh(&se_tpg->session_lock); -- 2.25.1
