This is a note to let you know that I've just added the patch titled scsi: libiscsi: Fix UAF in iscsi_conn_get_param()/iscsi_conn_teardown() to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: scsi-libiscsi-fix-uaf-in-iscsi_conn_get_param-iscsi_.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 03fe2cac4ea8f27512cb6368d4567f709fef99d1 Author: Lixiaokeng <lixiaokeng@xxxxxxxxxx> Date: Mon Dec 20 19:39:06 2021 +0800 scsi: libiscsi: Fix UAF in iscsi_conn_get_param()/iscsi_conn_teardown() [ Upstream commit 1b8d0300a3e9f216ae4901bab886db7299899ec6 ] |- iscsi_if_destroy_conn |-dev_attr_show |-iscsi_conn_teardown |-spin_lock_bh |-iscsi_sw_tcp_conn_get_param |-kfree(conn->persistent_address) |-iscsi_conn_get_param |-kfree(conn->local_ipaddr) ==>|-read persistent_address ==>|-read local_ipaddr |-spin_unlock_bh When iscsi_conn_teardown() and iscsi_conn_get_param() happen in parallel, a UAF may be triggered. Link: https://lore.kernel.org/r/046ec8a0-ce95-d3fc-3235-666a7c65b224@xxxxxxxxxx Reported-by: Lu Tixiong <lutianxiong@xxxxxxxxxx> Reviewed-by: Mike Christie <michael.christie@xxxxxxxxxx> Reviewed-by: Lee Duncan <lduncan@xxxxxxxx> Signed-off-by: Lixiaokeng <lixiaokeng@xxxxxxxxxx> Signed-off-by: Linfeilong <linfeilong@xxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index 30d27b6706746..d4e66c595eb87 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -2950,6 +2950,8 @@ 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; del_timer_sync(&conn->transport_timer); @@ -2971,8 +2973,6 @@ 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, @@ -2984,6 +2984,8 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn) mutex_unlock(&session->eh_mutex); iscsi_destroy_conn(cls_conn); + kfree(tmp_persistent_address); + kfree(tmp_local_ipaddr); } EXPORT_SYMBOL_GPL(iscsi_conn_teardown);