From 6a8d648c8d1824117a9e9edb948ed1611fb013c0 Mon Sep 17 00:00:00 2001 From: Alexander Usyskin Date: Sun, 17 Apr 2016 12:16:03 -0400 Subject: [PATCH] mei: fix NULL dereferencing during FW initiated disconnection In the case when disconnection is initiated from the FW the driver is flushing items from the write control list while iterating over it: mei_irq_write_handler() list_for_each_entry_safe(ctrl_wr_list) <-- outer loop mei_cl_irq_disconnect_rsp() mei_cl_set_disconnected() mei_io_list_flush(ctrl_wr_list) <-- destorying list We move the list flushing to the completion routine. Cc: #4.2+ Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mei/client.c | 4 ++++ drivers/misc/mei/hbm.c | 3 +-- drivers/misc/mei/interrupt.c | 5 +---- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c index bab17e4197b6..09f5280fa021 100644 --- a/drivers/misc/mei/client.c +++ b/drivers/misc/mei/client.c @@ -1766,6 +1766,10 @@ void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb) if (waitqueue_active(&cl->wait)) wake_up(&cl->wait); + break; + case MEI_FOP_DISCONNECT_RSP: + mei_io_cb_free(cb); + mei_cl_set_disconnected(cl); break; default: BUG_ON(0); diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c index 5eaa4638e824..5aa606c8a827 100644 --- a/drivers/misc/mei/hbm.c +++ b/drivers/misc/mei/hbm.c @@ -877,8 +877,7 @@ static int mei_hbm_fw_disconnect_req(struct mei_device *dev, cb = mei_io_cb_init(cl, MEI_FOP_DISCONNECT_RSP, NULL); if (!cb) return -ENOMEM; - cl_dbg(dev, cl, "add disconnect response as first\n"); - list_add(&cb->list, &dev->ctrl_wr_list.list); + list_add_tail(&cb->list, &dev->ctrl_wr_list.list); } return 0; } diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c index 1e5cb1f704f8..704dc6caad6d 100644 --- a/drivers/misc/mei/interrupt.c +++ b/drivers/misc/mei/interrupt.c @@ -194,10 +194,7 @@ static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb, return -EMSGSIZE; ret = mei_hbm_cl_disconnect_rsp(dev, cl); - mei_cl_set_disconnected(cl); - mei_io_cb_free(cb); - mei_me_cl_put(cl->me_cl); - cl->me_cl = NULL; + list_move_tail(&cb->list, &cmpl_list->list); return ret; } -- 2.30.2