| Message ID | 20180909204858.4257-1-alexandre.belloni@bootlin.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mfd: menelaus: fix possible race condition and leak | expand |
On Sun, 09 Sep 2018, Alexandre Belloni wrote: > The IRQ work is added before the struct rtc is allocated and registered, > but this struct is used in the IRQ handler. This may lead to a NULL pointer > dereference. > > Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc > before calling menelaus_add_irq_work. > > Also, this solves a possible leak as the RTC is never released. > > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > --- > > Lee, > > If that is ok with you, I would like to take this patch through the RTC > tree. So I can have a follow up patch removing rtc_device_register(). > > Thanks > > drivers/mfd/menelaus.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) Applied, thanks.
diff --git a/drivers/mfd/menelaus.c b/drivers/mfd/menelaus.c index 29b7164a823b..d28ebe7ecd21 100644 --- a/drivers/mfd/menelaus.c +++ b/drivers/mfd/menelaus.c @@ -1094,6 +1094,7 @@ static void menelaus_rtc_alarm_work(struct menelaus_chip *m) static inline void menelaus_rtc_init(struct menelaus_chip *m) { int alarm = (m->client->irq > 0); + int err; /* assume 32KDETEN pin is pulled high */ if (!(menelaus_read_reg(MENELAUS_OSC_CTRL) & 0x80)) { @@ -1101,6 +1102,12 @@ static inline void menelaus_rtc_init(struct menelaus_chip *m) return; } + m->rtc = devm_rtc_allocate_device(&m->client->dev); + if (IS_ERR(m->rtc)) + return; + + m->rtc->ops = &menelaus_rtc_ops; + /* support RTC alarm; it can issue wakeups */ if (alarm) { if (menelaus_add_irq_work(MENELAUS_RTCALM_IRQ, @@ -1125,10 +1132,8 @@ static inline void menelaus_rtc_init(struct menelaus_chip *m) menelaus_write_reg(MENELAUS_RTC_CTRL, m->rtc_control); } - m->rtc = rtc_device_register(DRIVER_NAME, - &m->client->dev, - &menelaus_rtc_ops, THIS_MODULE); - if (IS_ERR(m->rtc)) { + err = rtc_register_device(m->rtc); + if (err) { if (alarm) { menelaus_remove_irq_work(MENELAUS_RTCALM_IRQ); device_init_wakeup(&m->client->dev, 0);
The IRQ work is added before the struct rtc is allocated and registered, but this struct is used in the IRQ handler. This may lead to a NULL pointer dereference. Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc before calling menelaus_add_irq_work. Also, this solves a possible leak as the RTC is never released. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> --- Lee, If that is ok with you, I would like to take this patch through the RTC tree. So I can have a follow up patch removing rtc_device_register(). Thanks drivers/mfd/menelaus.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)