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mfd: menelaus: Fix possible race condition and leak

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[ Upstream commit 9612f8f503804d2fd2f63aa6ba1e58bba4612d96 ]

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>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alexandre Belloni 2018-09-09 22:48:58 +02:00 committed by Greg Kroah-Hartman
parent cd295fddbe
commit 128b1b38a6
1 changed files with 9 additions and 4 deletions
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13
drivers/mfd/menelaus.c
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@ -1094,6 +1094,7 @@ static void menelaus_rtc_alarm_work(struct menelaus_chip *m)
static inline void menelaus_rtc_init(struct menelaus_chip *m) static inline void menelaus_rtc_init(struct menelaus_chip *m)
{ {
int alarm = (m->client->irq > 0); int alarm = (m->client->irq > 0);
int err;
/* assume 32KDETEN pin is pulled high */ /* assume 32KDETEN pin is pulled high */
if (!(menelaus_read_reg(MENELAUS_OSC_CTRL) & 0x80)) { if (!(menelaus_read_reg(MENELAUS_OSC_CTRL) & 0x80)) {
@ -1101,6 +1102,12 @@ static inline void menelaus_rtc_init(struct menelaus_chip *m)
return; 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 */ /* support RTC alarm; it can issue wakeups */
if (alarm) { if (alarm) {
if (menelaus_add_irq_work(MENELAUS_RTCALM_IRQ, 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); menelaus_write_reg(MENELAUS_RTC_CTRL, m->rtc_control);
} }
m->rtc = rtc_device_register(DRIVER_NAME, err = rtc_register_device(m->rtc);
&m->client->dev, if (err) {
&menelaus_rtc_ops, THIS_MODULE);
if (IS_ERR(m->rtc)) {
if (alarm) { if (alarm) {
menelaus_remove_irq_work(MENELAUS_RTCALM_IRQ); menelaus_remove_irq_work(MENELAUS_RTCALM_IRQ);
device_init_wakeup(&m->client->dev, 0); device_init_wakeup(&m->client->dev, 0);