[PATCH net-next 1/2] nfc: s3fwrn5: fix order of freeing resources

From: Dmitry Torokhov
Date: Thu Sep 29 2022 - 01:04:48 EST


Caution needs to be exercised when mixing together regular and managed
resources. In case of this driver devm_request_threaded_irq() should
not be used, because it will result in the interrupt being freed too
late, and there being a chance that it fires up at an inopportune
moment and reference already freed data structures.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
drivers/nfc/s3fwrn5/i2c.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/nfc/s3fwrn5/i2c.c b/drivers/nfc/s3fwrn5/i2c.c
index f824dc7099ce..fb36860df81c 100644
--- a/drivers/nfc/s3fwrn5/i2c.c
+++ b/drivers/nfc/s3fwrn5/i2c.c
@@ -231,9 +231,9 @@ static int s3fwrn5_i2c_probe(struct i2c_client *client,
if (ret < 0)
goto disable_clk;

- ret = devm_request_threaded_irq(&client->dev, phy->i2c_dev->irq, NULL,
- s3fwrn5_i2c_irq_thread_fn, IRQF_ONESHOT,
- S3FWRN5_I2C_DRIVER_NAME, phy);
+ ret = request_threaded_irq(phy->i2c_dev->irq,
+ NULL, s3fwrn5_i2c_irq_thread_fn,
+ IRQF_ONESHOT, S3FWRN5_I2C_DRIVER_NAME, phy);
if (ret)
goto s3fwrn5_remove;

@@ -250,6 +250,7 @@ static void s3fwrn5_i2c_remove(struct i2c_client *client)
{
struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);

+ free_irq(phy->i2c_dev->irq, phy);
s3fwrn5_remove(phy->common.ndev);
clk_disable_unprepare(phy->clk);
}
--
2.38.0.rc1.362.ged0d419d3c-goog