2018-11-07 21:31:32

by Janusz Krzysztofik

Subject: [PATCH] ARM: OMAP1: ams-delta: Fix possible use of uninitialized field

While playing with initialization order of modem device, it has been
discovered that under some circumstances (early console init, I
believe) its .pm() callback may be called before the
uart_port->private_data pointer is initialized from
plat_serial8250_port->private_data, resulting in NULL pointer
dereference. Fix it by checking for uninitialized pointer before using
it in modem_pm().

Fixes: aabf31737a6a ("ARM: OMAP1: ams-delta: update the modem to use regulator API")
Signed-off-by: Janusz Krzysztofik <[email protected]>
---
arch/arm/mach-omap1/board-ams-delta.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/arm/mach-omap1/board-ams-delta.c b/arch/arm/mach-omap1/board-ams-delta.c
index 1947bc63074e..17e0b386e1b2 100644
--- a/arch/arm/mach-omap1/board-ams-delta.c
+++ b/arch/arm/mach-omap1/board-ams-delta.c
@@ -764,6 +764,9 @@ static void modem_pm(struct uart_port *port, unsigned int state, unsigned old)
struct modem_private_data *priv = port->private_data;
int ret;

+ if (!priv)
+ return;
+
if (IS_ERR(priv->regulator))
return;

--
2.16.4

2018-11-08 17:28:59

by Tony Lindgren

Subject: Re: [PATCH] ARM: OMAP1: ams-delta: Fix possible use of uninitialized field

* Janusz Krzysztofik <[email protected]> [181107 13:28]:
> While playing with initialization order of modem device, it has been
> discovered that under some circumstances (early console init, I
> believe) its .pm() callback may be called before the
> uart_port->private_data pointer is initialized from
> plat_serial8250_port->private_data, resulting in NULL pointer
> dereference. Fix it by checking for uninitialized pointer before using
> it in modem_pm().

Applying into omap-for-v4.20/fixes thanks.

Tony