Skip to contentSkip to conversation

FAILED: patch "[PATCH] rapidio: fix rio_dma_transfer error handling" failed to apply to 4.16-stable tree

PATCH [email protected] 1 participant 1 message Apr 22, 2018

Subsystems (2)
Stable branch Rapidio
lore
Share & tools
lore

[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 4.16-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From c5157b76869ba98c3a99a1982396437464e131a6 Mon Sep 17 00:00:00 2001

From: Ioan Nicu <[email protected]>
Date: Fri, 20 Apr 2018 14:55:49 -0700
Subject: [PATCH] rapidio: fix rio_dma_transfer error handling

Some of the mport_dma_req structure members were initialized late inside the do_dma_request() function, just before submitting the request to the dma engine. But we have some error branches before that. In case of such an error, the code would return on the error path and trigger the calling of dma_req_free() with a req structure which is not completely initialized. This causes a NULL pointer dereference in dma_req_free().

This patch fixes these error branches by making sure that all necessary mport_dma_req structure members are initialized in rio_dma_transfer() immediately after the request structure gets allocated.

Link http://lkml.kernel.org/r/[email protected] open here
Fixes bbd876adb8c72 ("rapidio: use a reference count for struct mport_dma_req")
Signed-off-by Ioan Nicu <[email protected]>
Tested-by Alexander Sverdlin <[email protected]>
Acked-by Alexandre Bounine <[email protected]>
Cc Barry Wood <[email protected]>
Cc Matt Porter <[email protected]>
Cc Christophe JAILLET <[email protected]>
Cc Logan Gunthorpe <[email protected]>
Cc Chris Wilson <[email protected]>
Cc Tvrtko Ursulin <[email protected]>
Cc Frank Kunz <[email protected]>
Cc <[email protected]> [4.6+]
Signed-off-by Andrew Morton <[email protected]>
Signed-off-by Linus Torvalds <[email protected]>
drivers/rapidio/devices/rio_mport_cdev.c +9 -10
index 9d27016c899e..0434ab7b6497 100644
@@ -740,10 +740,7 @@ static int do_dma_request(struct mport_dma_req *req,
 	tx->callback = dma_xfer_callback;
 	tx->callback_param = req;
 
-	req->dmach = chan;
-	req->sync = sync;
 	req->status = DMA_IN_PROGRESS;
-	init_completion(&req->req_comp);
 	kref_get(&req->refcount);
 
 	cookie = dmaengine_submit(tx);

@@ -831,13 +828,20 @@ rio_dma_transfer(struct file *filp, u32 transfer_mode,
 	if (!req)
 		return -ENOMEM;
 
-	kref_init(&req->refcount);
-
 	ret = get_dma_channel(priv);
 	if (ret) {
 		kfree(req);
 		return ret;
 	}
+	chan = priv->dmach;
+
+	kref_init(&req->refcount);
+	init_completion(&req->req_comp);
+	req->dir = dir;
+	req->filp = filp;
+	req->priv = priv;
+	req->dmach = chan;
+	req->sync = sync;
 
 	/*
 	 * If parameter loc_addr != NULL, we are transferring data from/to

@@ -925,11 +929,6 @@ rio_dma_transfer(struct file *filp, u32 transfer_mode,
 				xfer->offset, xfer->length);
 	}
 
-	req->dir = dir;
-	req->filp = filp;
-	req->priv = priv;
-	chan = priv->dmach;
-
 	nents = dma_map_sg(chan->device->dev,
 			   req->sgt.sgl, req->sgt.nents, dir);
 	if (nents == 0) {