From: Kangjie Lu <kjlu@umn.edu>
To: kjlu@umn.edu
Cc: pakki001@umn.edu, Richard Genoud <richard.genoud@gmail.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>,
Nicolas Ferre <nicolas.ferre@microchip.com>,
Alexandre Belloni <alexandre.belloni@bootlin.com>,
Ludovic Desroches <ludovic.desroches@microchip.com>,
linux-serial@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] tty: atmel_serial: fix a NULL pointer dereference
Date: Thu, 14 Mar 2019 02:17:59 -0500 [thread overview]
Message-ID: <20190314071759.18845-1-kjlu@umn.edu> (raw)
In case dmaengine_prep_dma_cyclic fails, the fix return a proper
error code to avoid NULL pointer dereference.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
---
drivers/tty/serial/atmel_serial.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 05147fe24343..cf560d05008c 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -1237,8 +1237,10 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
dma_cap_set(DMA_CYCLIC, mask);
atmel_port->chan_rx = dma_request_slave_channel(mfd_dev, "rx");
- if (atmel_port->chan_rx == NULL)
+ if (atmel_port->chan_rx == NULL) {
+ ret = -EINVAL;
goto chan_err;
+ }
dev_info(port->dev, "using %s for rx DMA transfers\n",
dma_chan_name(atmel_port->chan_rx));
@@ -1257,6 +1259,7 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
if (!nent) {
dev_dbg(port->dev, "need to release resource of dma\n");
+ ret = -EINVAL;
goto chan_err;
} else {
dev_dbg(port->dev, "%s: mapped %d@%p to %pad\n", __func__,
@@ -1288,6 +1291,11 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
sg_dma_len(&atmel_port->sg_rx)/2,
DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT);
+ if (!desc) {
+ dev_err(port->dev, "Preparing DMA cyclic failed\n");
+ ret = -ENOMEM;
+ goto chan_err;
+ }
desc->callback = atmel_complete_rx_dma;
desc->callback_param = port;
atmel_port->desc_rx = desc;
@@ -1300,7 +1308,7 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
atmel_port->use_dma_rx = 0;
if (atmel_port->chan_rx)
atmel_release_rx_dma(port);
- return -EINVAL;
+ return ret;
}
static void atmel_uart_timer_callback(struct timer_list *t)
--
2.17.1
next reply other threads:[~2019-03-14 7:18 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-14 7:17 Kangjie Lu [this message]
2019-03-14 8:25 ` [PATCH] tty: atmel_serial: fix a NULL pointer dereference Richard Genoud
2019-03-15 7:21 ` [PATCH v2] " Kangjie Lu
2019-03-15 8:22 Richard Genoud
2019-03-15 17:16 ` [PATCH] " Kangjie Lu
2019-03-18 7:28 ` Richard Genoud
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=20190314071759.18845-1-kjlu@umn.edu \
--to=kjlu@umn.edu \
--cc=alexandre.belloni@bootlin.com \
--cc=gregkh@linuxfoundation.org \
--cc=jslaby@suse.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
--cc=ludovic.desroches@microchip.com \
--cc=nicolas.ferre@microchip.com \
--cc=pakki001@umn.edu \
--cc=richard.genoud@gmail.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).