commit 1b8d0300a3e9 ("scsi: libiscsi: Fix UAF in
iscsi_conn_get_param()/iscsi_conn_teardown()") fixed an UAF in
iscsi_conn_get_param() and introduced 2 tmp_xxx varibles, the
implement looks ugly.We can fix this UAF with the help of device_del() gracefully. Call iscsi_remove_conn() at the beginning of iscsi_conn_teardown would make userspace unable to see iscsi_cls_conn any more, then we can free memory safely. And remove iscsi_destroy_conn() by hand since it is not used now. Signed-off-by: Wenchao Hao <[email protected]> Signed-off-by: Wu Bo <[email protected]> --- drivers/scsi/libiscsi.c | 10 +++++----- drivers/scsi/scsi_transport_iscsi.c | 27 +++++---------------------- include/scsi/scsi_transport_iscsi.h | 1 - 3 files changed, 10 insertions(+), 28 deletions(-) diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index 38e68b449c08..da583a39b307 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -3109,8 +3109,8 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn) { struct iscsi_conn *conn = cls_conn->dd_data; struct iscsi_session *session = conn->session; - char *tmp_persistent_address = conn->persistent_address; - char *tmp_local_ipaddr = conn->local_ipaddr; + + iscsi_remove_conn(cls_conn); del_timer_sync(&conn->transport_timer); @@ -3132,6 +3132,8 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn) spin_lock_bh(&session->frwd_lock); free_pages((unsigned long) conn->data, get_order(ISCSI_DEF_MAX_RECV_SEG_LEN)); + kfree(conn->persistent_address); + kfree(conn->local_ipaddr); /* regular RX path uses back_lock */ spin_lock_bh(&session->back_lock); kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task, @@ -3142,9 +3144,7 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn) spin_unlock_bh(&session->frwd_lock); mutex_unlock(&session->eh_mutex); - iscsi_destroy_conn(cls_conn); - kfree(tmp_persistent_address); - kfree(tmp_local_ipaddr); + iscsi_put_conn(cls_conn); } EXPORT_SYMBOL_GPL(iscsi_conn_teardown); diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index fc33000a6af9..d0f996d14782 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -2165,7 +2165,11 @@ static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data) { if (!iscsi_is_conn_dev(dev)) return 0; - return iscsi_destroy_conn(iscsi_dev_to_conn(dev)); + + iscsi_remove_conn(iscsi_dev_to_conn(dev)); + iscsi_put_conn(iscsi_dev_to_conn(dev)); + + return 0; } void iscsi_remove_session(struct iscsi_cls_session *session) @@ -2437,27 +2441,6 @@ void iscsi_remove_conn(struct iscsi_cls_conn *conn) } EXPORT_SYMBOL_GPL(iscsi_remove_conn); -/** - * iscsi_destroy_conn - destroy iscsi class connection - * @conn: iscsi cls session - * - * This can be called from a LLD or iscsi_transport. - */ -int iscsi_destroy_conn(struct iscsi_cls_conn *conn) -{ - unsigned long flags; - - spin_lock_irqsave(&connlock, flags); - list_del(&conn->conn_list); - spin_unlock_irqrestore(&connlock, flags); - - transport_unregister_device(&conn->dev); - ISCSI_DBG_TRANS_CONN(conn, "Completing conn destruction\n"); - device_unregister(&conn->dev); - return 0; -} -EXPORT_SYMBOL_GPL(iscsi_destroy_conn); - void iscsi_put_conn(struct iscsi_cls_conn *conn) { put_device(&conn->dev); diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h index 4af6768e8195..aedbc4488149 100644 --- a/include/scsi/scsi_transport_iscsi.h +++ b/include/scsi/scsi_transport_iscsi.h @@ -447,7 +447,6 @@ extern int iscsi_add_conn(struct iscsi_cls_conn *conn); extern void iscsi_remove_conn(struct iscsi_cls_conn *conn); extern void iscsi_put_conn(struct iscsi_cls_conn *conn); extern void iscsi_get_conn(struct iscsi_cls_conn *conn); -extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn); extern void iscsi_unblock_session(struct iscsi_cls_session *session); extern void iscsi_block_session(struct iscsi_cls_session *session); extern int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time); -- 2.32.0 -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/open-iscsi/20220310015759.3296841-4-haowenchao%40huawei.com.
