dmaengine Archive on lore.kernel.org
 help / color / Atom feed
From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: vkoul@kernel.org, dan.j.williams@intel.com
Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
	Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [PATCH] dma: mv_xor: Fix a possible null-pointer dereference in mv_xor_prep_dma_xor()
Date: Sat, 27 Jul 2019 17:30:27 +0800
Message-ID: <20190727093027.11781-1-baijiaju1990@gmail.com> (raw)

In mv_xor_prep_dma_xor(), there is an if statement on line 577 to check
whether sw_desc is NULL:
    if (sw_desc)

When sw_desc is NULL, it is used on line 594:
    dev_dbg(..., sw_desc, &sw_desc->async_tx);

Thus, a possible null-pointer dereference may occur.

To fix this bug, sw_desc is checked before being used.

This bug is found by a static analysis tool STCheck written by us.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
 drivers/dma/mv_xor.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
index 0ac8e7b34e12..08c0b2a9eb32 100644
--- a/drivers/dma/mv_xor.c
+++ b/drivers/dma/mv_xor.c
@@ -589,9 +589,11 @@ mv_xor_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
 		}
 	}
 
-	dev_dbg(mv_chan_to_devp(mv_chan),
-		"%s sw_desc %p async_tx %p \n",
-		__func__, sw_desc, &sw_desc->async_tx);
+	if (sw_desc) {
+		dev_dbg(mv_chan_to_devp(mv_chan),
+			"%s sw_desc %p async_tx %p \n",
+			__func__, sw_desc, &sw_desc->async_tx);
+	}
 	return sw_desc ? &sw_desc->async_tx : NULL;
 }
 
-- 
2.17.0


             reply index

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-27  9:30 Jia-Ju Bai [this message]
2019-08-08 13:21 ` Vinod Koul

Reply instructions:

You may reply publically 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=20190727093027.11781-1-baijiaju1990@gmail.com \
    --to=baijiaju1990@gmail.com \
    --cc=dan.j.williams@intel.com \
    --cc=dmaengine@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=vkoul@kernel.org \
    /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

dmaengine Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/dmaengine/0 dmaengine/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 dmaengine dmaengine/ https://lore.kernel.org/dmaengine \
		dmaengine@vger.kernel.org dmaengine@archiver.kernel.org
	public-inbox-index dmaengine


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.dmaengine


AGPL code for this site: git clone https://public-inbox.org/ public-inbox