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From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Lee Jones <lee.jones@linaro.org>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 3.18 22/22] mfd: menelaus: Fix possible race condition and leak
Date: Wed, 31 Oct 2018 19:12:06 -0400	[thread overview]
Message-ID: <20181031231206.29509-22-sashal@kernel.org> (raw)
In-Reply-To: <20181031231206.29509-1-sashal@kernel.org>

From: Alexandre Belloni <alexandre.belloni@bootlin.com>

[ 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>
---
 drivers/mfd/menelaus.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/mfd/menelaus.c b/drivers/mfd/menelaus.c
index 9f01aef539dd..8fcb503daae1 100644
--- a/drivers/mfd/menelaus.c
+++ b/drivers/mfd/menelaus.c
@@ -1121,6 +1121,7 @@ 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)) {
@@ -1128,6 +1129,12 @@ 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,
@@ -1152,10 +1159,8 @@ 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);
-- 
2.17.1


  parent reply	other threads:[~2018-10-31 23:12 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-31 23:11 [PATCH AUTOSEL 3.18 01/22] locking/lockdep: Fix debug_locks off performance problem Sasha Levin
2018-10-31 23:11 ` [PATCH AUTOSEL 3.18 02/22] ataflop: fix error handling during setup Sasha Levin
2018-10-31 23:11 ` [PATCH AUTOSEL 3.18 03/22] swim: fix cleanup on setup error Sasha Levin
2018-10-31 23:11 ` [PATCH AUTOSEL 3.18 04/22] tun: Consistently configure generic netdev params via rtnetlink Sasha Levin
2018-10-31 23:11 ` [PATCH AUTOSEL 3.18 05/22] perf tools: Free temporary 'sys' string in read_event_files() Sasha Levin
2018-10-31 23:11 ` [PATCH AUTOSEL 3.18 06/22] perf tools: Cleanup trace-event-info 'tdata' leak Sasha Levin
2018-10-31 23:11 ` [PATCH AUTOSEL 3.18 07/22] cpupower: Fix coredump on VMWare Sasha Levin
2018-10-31 23:11 ` [PATCH AUTOSEL 3.18 08/22] mmc: sdhci-pci-o2micro: Add quirk for O2 Micro dev 0x8620 rev 0x01 Sasha Levin
2018-10-31 23:11 ` [PATCH AUTOSEL 3.18 09/22] x86/olpc: Indicate that legacy PC XO-1 platform should not register RTC Sasha Levin
2018-10-31 23:11 ` [PATCH AUTOSEL 3.18 10/22] regulator: fixed: Default enable high on DT regulators Sasha Levin
2018-10-31 23:11 ` [PATCH AUTOSEL 3.18 11/22] x86: boot: Fix EFI stub alignment Sasha Levin
2018-10-31 23:11 ` [PATCH AUTOSEL 3.18 12/22] kprobes: Return error if we fail to reuse kprobe instead of BUG_ON() Sasha Levin
2018-10-31 23:11 ` [PATCH AUTOSEL 3.18 13/22] ath10k: schedule hardware restart if WMI command times out Sasha Levin
2018-10-31 23:11 ` [PATCH AUTOSEL 3.18 14/22] scsi: esp_scsi: Track residual for PIO transfers Sasha Levin
2018-10-31 23:11 ` [PATCH AUTOSEL 3.18 15/22] Drivers: hv: kvp: Fix two "this statement may fall through" warnings Sasha Levin
2018-10-31 23:12 ` [PATCH AUTOSEL 3.18 16/22] ext4: fix argument checking in EXT4_IOC_MOVE_EXT Sasha Levin
2018-10-31 23:12 ` [PATCH AUTOSEL 3.18 17/22] MD: fix invalid stored role for a disk Sasha Levin
2018-10-31 23:12 ` [PATCH AUTOSEL 3.18 18/22] usb: chipidea: Prevent unbalanced IRQ disable Sasha Levin
2018-10-31 23:12 ` [PATCH AUTOSEL 3.18 19/22] uio: ensure class is registered before devices Sasha Levin
2018-10-31 23:12 ` [PATCH AUTOSEL 3.18 20/22] scsi: lpfc: Correct soft lockup when running mds diagnostics Sasha Levin
2018-10-31 23:12 ` [PATCH AUTOSEL 3.18 21/22] signal: Always deliver the kernel's SIGKILL and SIGSTOP to a pid namespace init Sasha Levin
2018-10-31 23:12 ` Sasha Levin [this message]
2018-11-01  0:27   ` [PATCH AUTOSEL 3.18 22/22] mfd: menelaus: Fix possible race condition and leak Alexandre Belloni
2018-11-01  1:29     ` Sasha Levin

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