From: Alain Volmat <alain.volmat@foss.st.com>
To: <wsa@kernel.org>, <pierre-yves.mordret@foss.st.com>
Cc: <alexandre.torgue@foss.st.com>, <linux-i2c@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <fabrice.gasnier@foss.st.com>,
<amelie.delaunay@foss.st.com>, <alain.volmat@foss.st.com>
Subject: [PATCH 3/3] i2c: stm32f7: prevent calling slave handling if no slave running
Date: Wed, 30 Jun 2021 16:11:43 +0200 [thread overview]
Message-ID: <1625062303-15327-4-git-send-email-alain.volmat@foss.st.com> (raw)
In-Reply-To: <1625062303-15327-1-git-send-email-alain.volmat@foss.st.com>
Slave interrupt handler should only be called if there is actually
a slave registered and running to avoid accessing an invalid pointer.
Without this commit, an OOPS can be generated due to a NULL ptr dereference
while receiving an IT when there is no master transfer and no slave
running:
- stm32f7_i2c_isr_event
- no master_mode hence calling stm32f7_i2c_slave_isr_event
- access to i2c_dev->slave_running leading to oops due to
slave_running being NULL.
Fixes: 60d609f30de2 ("i2c: i2c-stm32f7: Add slave support")
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
---
drivers/i2c/busses/i2c-stm32f7.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index 0d99c075deb2..2cc9bb0f6d7f 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -1497,10 +1497,14 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
u32 status, mask;
int ret = IRQ_HANDLED;
- /* Check if the interrupt if for a slave device */
+ /* Check if the interrupt is for a slave device */
if (!i2c_dev->master_mode) {
- ret = stm32f7_i2c_slave_isr_event(i2c_dev);
- return ret;
+ if (i2c_dev->slave_running)
+ return stm32f7_i2c_slave_isr_event(i2c_dev);
+
+ dev_warn_ratelimited(i2c_dev->dev,
+ "Unexpected IT received: ISR:0x%x\n",
+ readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR));
}
status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
--
2.25.1
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next prev parent reply other threads:[~2021-06-30 14:32 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-30 14:11 [PATCH 0/3] i2c: stm32f7: several fixes in error cases Alain Volmat
2021-06-30 14:11 ` [PATCH 1/3] i2c: stm32f7: recover the bus on access timeout Alain Volmat
2021-06-30 14:11 ` [PATCH 2/3] i2c: stm32f7: flush TX FIFO upon transfer errors Alain Volmat
2021-06-30 14:11 ` Alain Volmat [this message]
2021-11-29 12:21 ` [PATCH 3/3] i2c: stm32f7: prevent calling slave handling if no slave running Wolfram Sang
2021-11-29 12:25 ` Alain Volmat
2021-07-01 8:51 ` [PATCH 0/3] i2c: stm32f7: several fixes in error cases Alain Volmat
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