From: Wenchao Hao <haowenchao@huawei.com> mainline inclusion from mainline-v5.18-rc1 commit 8709c323091be019f76a49cf783052a5636aca85 category: bugfix bugzilla: 187381, https://gitee.com/openeuler/kernel/issues/I5LBFL CVE: NA -------------------------------- 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. We can gracefully fix this UAF with the help of device_del(). Calling iscsi_remove_conn() at the beginning of iscsi_conn_teardown would make userspace unable to see iscsi_cls_conn. This way we we can free memory safely. Remove iscsi_destroy_conn() since it is no longer used. Link: https://lore.kernel.org/r/20220310015759.3296841-4-haowenchao@huawei.com Reviewed-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Wenchao Hao <haowenchao@huawei.com> Signed-off-by: Wu Bo <wubo40@huawei.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Conflict: iscsi_destroy_conn() is not removed. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- drivers/scsi/libiscsi.c | 10 +++++----- drivers/scsi/scsi_transport_iscsi.c | 6 +++++- 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index 072c6b85cb30..9f625a4d53c0 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -3142,8 +3142,8 @@ 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); @@ -3167,6 +3167,8 @@ 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, @@ -3177,9 +3179,7 @@ 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 eba74ac58735..e50fbcce55aa 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -2142,7 +2142,11 @@ 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) -- 2.25.1