From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sebastian von Ohr <vonohr@smaract.com>,
Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>,
Vinod Koul <vkoul@kernel.org>, Sasha Levin <sashal@kernel.org>,
dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: [PATCH AUTOSEL 5.6 05/50] dmaengine: xilinx_dma: Add missing check for empty list
Date: Thu, 7 May 2020 10:26:41 -0400 [thread overview]
Message-ID: <20200507142726.25751-5-sashal@kernel.org> (raw)
In-Reply-To: <20200507142726.25751-1-sashal@kernel.org>
From: Sebastian von Ohr <vonohr@smaract.com>
[ Upstream commit b269426011bcfd97b7c3101abfe1a99147b6f40b ]
The DMA transfer might finish just after checking the state with
dma_cookie_status, but before the lock is acquired. Not checking
for an empty list in xilinx_dma_tx_status may result in reading
random data or data corruption when desc is written to. This can
be reliably triggered by using dma_sync_wait to wait for DMA
completion.
Signed-off-by: Sebastian von Ohr <vonohr@smaract.com>
Tested-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Link: https://lore.kernel.org/r/20200303130518.333-1-vonohr@smaract.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/dma/xilinx/xilinx_dma.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index a9c5d5cc9f2bd..5d5f1d0ce16cb 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -1229,16 +1229,16 @@ static enum dma_status xilinx_dma_tx_status(struct dma_chan *dchan,
return ret;
spin_lock_irqsave(&chan->lock, flags);
-
- desc = list_last_entry(&chan->active_list,
- struct xilinx_dma_tx_descriptor, node);
- /*
- * VDMA and simple mode do not support residue reporting, so the
- * residue field will always be 0.
- */
- if (chan->has_sg && chan->xdev->dma_config->dmatype != XDMA_TYPE_VDMA)
- residue = xilinx_dma_get_residue(chan, desc);
-
+ if (!list_empty(&chan->active_list)) {
+ desc = list_last_entry(&chan->active_list,
+ struct xilinx_dma_tx_descriptor, node);
+ /*
+ * VDMA and simple mode do not support residue reporting, so the
+ * residue field will always be 0.
+ */
+ if (chan->has_sg && chan->xdev->dma_config->dmatype != XDMA_TYPE_VDMA)
+ residue = xilinx_dma_get_residue(chan, desc);
+ }
spin_unlock_irqrestore(&chan->lock, flags);
dma_set_residue(txstate, residue);
--
2.20.1
next prev parent reply other threads:[~2020-05-07 14:27 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200507142726.25751-1-sashal@kernel.org>
2020-05-07 14:26 ` [PATCH AUTOSEL 5.6 03/50] dmaengine: hisilicon: Fix build error without PCI_MSI Sasha Levin
2020-05-07 14:26 ` [PATCH AUTOSEL 5.6 04/50] dmaengine: ti: k3-psil: fix deadlock on error path Sasha Levin
2020-05-07 14:26 ` Sasha Levin [this message]
2020-05-07 14:26 ` [PATCH AUTOSEL 5.6 16/50] dmaengine: pch_dma.c: Avoid data race between probe and irq handler Sasha Levin
2020-05-07 14:26 ` [PATCH AUTOSEL 5.6 17/50] dmaengine: mmp_tdma: Do not ignore slave config validation errors Sasha Levin
2020-05-07 14:26 ` [PATCH AUTOSEL 5.6 18/50] dmaengine: mmp_tdma: Reset channel error on release Sasha Levin
2020-05-07 14:27 ` [PATCH AUTOSEL 5.6 27/50] dmaengine: fix channel index enumeration Sasha Levin
2020-05-07 14:27 ` [PATCH AUTOSEL 5.6 28/50] dmaengine: dmatest: Fix iteration non-stop logic Sasha Levin
2020-05-07 14:27 ` [PATCH AUTOSEL 5.6 31/50] dmaengine: dmatest: Fix process hang when reading 'wait' parameter Sasha Levin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200507142726.25751-5-sashal@kernel.org \
--to=sashal@kernel.org \
--cc=dmaengine@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=radhey.shyam.pandey@xilinx.com \
--cc=stable@vger.kernel.org \
--cc=vkoul@kernel.org \
--cc=vonohr@smaract.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).