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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/20180412150605.GA31409@nokia.com
Fixes: bbd876adb8 ("rapidio: use a reference count for struct mport_dma_req")
Signed-off-by: Ioan Nicu <ioan.nicu.ext@nokia.com>
Tested-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Acked-by: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Barry Wood <barry.wood@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Frank Kunz <frank.kunz@nokia.com>
Cc: <stable@vger.kernel.org>	[4.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ioan Nicu 2018-04-20 14:55:49 -07:00 committed by Linus Torvalds
parent e71769ae52
commit c5157b7686
1 changed files with 9 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
drivers/rapidio/devices/rio_mport_cdev.c
View File

@ -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) {