On 2023-01-25 09:33, Dmitry Bogdanov wrote:
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>
---
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 f6008675dd3f..0748cbfb9631 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -4521,6 +4521,9 @@ 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
@@ -4544,9 +4547,6 @@ 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);
I have not had any more issues since applying the patch, which is good
news :)
Will this be backported to earlier stable kernels like 5.15.x and 6.1.x
Regards,
Forza
