* [PATCH] serial: 8250_fintek: Fix potential NULL pointer dereference
@ 2016-06-28 1:46 Ji-Ze Hong (Peter Hong)
2016-08-18 16:22 ` Ricardo Ribalda Delgado
0 siblings, 1 reply; 2+ messages in thread
From: Ji-Ze Hong (Peter Hong) @ 2016-06-28 1:46 UTC (permalink / raw)
To: gregkh, jslaby, ricardo.ribalda
Cc: alan, peter, tom_tsai, peter_hong, linux-serial, linux-kernel,
Ji-Ze Hong (Peter Hong)
Fix potential NULL pointer dereference on
'commit 4da22f1418cb ("serial: 8250_fintek: fix the mismatched IRQ mode")'
We try to fix IRQ mode mismatch issue and add the following code to
detect IRQ Level or Edge mode.
struct irq_data *irq_data = irq_get_irq_data(uart->port.irq);
bool level_mode = irqd_is_level_type(irq_data);
But *irq_data had not any check and pass to irqd_is_level_type(),
it may lead to potential NULL pointer dereference.
Also modify detecting IRQ mode when fintek chip found.
Suggested-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
---
drivers/tty/serial/8250/8250_fintek.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c
index 737b4b3..9119d0c 100644
--- a/drivers/tty/serial/8250/8250_fintek.c
+++ b/drivers/tty/serial/8250/8250_fintek.c
@@ -212,8 +212,8 @@ int fintek_8250_probe(struct uart_8250_port *uart)
{
struct fintek_8250 *pdata;
struct fintek_8250 probe_data;
- struct irq_data *irq_data = irq_get_irq_data(uart->port.irq);
- bool level_mode = irqd_is_level_type(irq_data);
+ struct irq_data *irq_data;
+ bool level_mode = false; /* Default to Edge/High */
if (find_base_port(&probe_data, uart->port.iobase))
return -ENODEV;
@@ -226,5 +226,14 @@ int fintek_8250_probe(struct uart_8250_port *uart)
uart->port.rs485_config = fintek_8250_rs485_config;
uart->port.private_data = pdata;
+ irq_data = irq_get_irq_data(uart->port.irq);
+ if (irq_data) {
+ level_mode = irqd_is_level_type(irq_data);
+ } else {
+ dev_warn(uart->port.dev,
+ "%s: Can't get irq_data, set this port to Edge/High",
+ __func__);
+ }
+
return fintek_8250_set_irq_mode(pdata, level_mode);
}
--
1.9.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] serial: 8250_fintek: Fix potential NULL pointer dereference
2016-06-28 1:46 [PATCH] serial: 8250_fintek: Fix potential NULL pointer dereference Ji-Ze Hong (Peter Hong)
@ 2016-08-18 16:22 ` Ricardo Ribalda Delgado
0 siblings, 0 replies; 2+ messages in thread
From: Ricardo Ribalda Delgado @ 2016-08-18 16:22 UTC (permalink / raw)
To: Ji-Ze Hong (Peter Hong)
Cc: Greg Kroah-Hartman, Jiri Slaby, Alan Cox, Peter Hurley,
PA20 TOM TSAI 蔡宗佑,
Peter H, linux-serial, LKML, Ji-Ze Hong (Peter Hong)
Hi Peter
Somehow this patch entered my mail limbo. Sorry about that.
Could you remove the brackets on the if/else? I think that for one
liners they are not recommended.
Also, I think it might be a good a idea to remove the __func__ from
the dev_warn.
Best regards!
On Tue, Jun 28, 2016 at 3:46 AM, Ji-Ze Hong (Peter Hong)
<hpeter@gmail.com> wrote:
> Fix potential NULL pointer dereference on
> 'commit 4da22f1418cb ("serial: 8250_fintek: fix the mismatched IRQ mode")'
>
> We try to fix IRQ mode mismatch issue and add the following code to
> detect IRQ Level or Edge mode.
>
> struct irq_data *irq_data = irq_get_irq_data(uart->port.irq);
> bool level_mode = irqd_is_level_type(irq_data);
>
> But *irq_data had not any check and pass to irqd_is_level_type(),
> it may lead to potential NULL pointer dereference.
>
> Also modify detecting IRQ mode when fintek chip found.
>
> Suggested-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
> Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
> ---
> drivers/tty/serial/8250/8250_fintek.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c
> index 737b4b3..9119d0c 100644
> --- a/drivers/tty/serial/8250/8250_fintek.c
> +++ b/drivers/tty/serial/8250/8250_fintek.c
> @@ -212,8 +212,8 @@ int fintek_8250_probe(struct uart_8250_port *uart)
> {
> struct fintek_8250 *pdata;
> struct fintek_8250 probe_data;
> - struct irq_data *irq_data = irq_get_irq_data(uart->port.irq);
> - bool level_mode = irqd_is_level_type(irq_data);
> + struct irq_data *irq_data;
> + bool level_mode = false; /* Default to Edge/High */
>
> if (find_base_port(&probe_data, uart->port.iobase))
> return -ENODEV;
> @@ -226,5 +226,14 @@ int fintek_8250_probe(struct uart_8250_port *uart)
> uart->port.rs485_config = fintek_8250_rs485_config;
> uart->port.private_data = pdata;
>
> + irq_data = irq_get_irq_data(uart->port.irq);
> + if (irq_data) {
> + level_mode = irqd_is_level_type(irq_data);
> + } else {
> + dev_warn(uart->port.dev,
> + "%s: Can't get irq_data, set this port to Edge/High",
> + __func__);
> + }
> +
> return fintek_8250_set_irq_mode(pdata, level_mode);
> }
> --
> 1.9.1
>
--
Ricardo Ribalda
^ permalink raw reply [flat|nested] 2+ messages in thread
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2016-08-18 16:22 ` Ricardo Ribalda Delgado
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