From: Hans de Goede Date: Sun, 23 May 2021 17:00:55 +0000 (+0200) Subject: iio: accel: bmc150: Fix dereferencing the wrong pointer in bmc150_get/set_second_device X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f2bf22dc9ea8ead180fc0221874bd556bf1d2685;p=linux.git iio: accel: bmc150: Fix dereferencing the wrong pointer in bmc150_get/set_second_device The drvdata for iio-parent devices points to the struct iio_dev for the iio-device. So by directly casting the return from i2c_get_clientdata() to struct bmc150_accel_data * the code was ending up storing the second_dev pointer in (and retrieving it from) some semi-random offset inside struct iio_dev, rather then storing it in the second_dev member of the bmc150_accel_data struct. Fix the code to get the struct bmc150_accel_data * pointer to call iio_priv() on the struct iio_dev * returned by i2c_get_clientdata(), so that the correct pointer gets dereferenced. This fixes the following oops on rmmod, caused by trying to dereference the wrong return of bmc150_get_second_device(): [ 238.980737] BUG: unable to handle page fault for address: 0000000000004710 [ 238.980755] #PF: supervisor read access in kernel mode [ 238.980760] #PF: error_code(0x0000) - not-present page ... [ 238.980841] i2c_unregister_device.part.0+0x19/0x60 [ 238.980856] 0xffffffffc0815016 [ 238.980863] i2c_device_remove+0x25/0xb0 [ 238.980869] __device_release_driver+0x180/0x240 [ 238.980876] driver_detach+0xd4/0x120 [ 238.980882] bus_remove_driver+0x5b/0xd0 [ 238.980888] i2c_del_driver+0x44/0x70 While at it also remove the now no longer sensible checks for data being NULL, iio_priv never returns NULL for an iio_dev with non 0 sized private-data. Fixes: 5bfb3a4bd8f6 ("iio: accel: bmc150: Check for a second ACPI device for BOSC0200") Cc: Jeremy Cline Signed-off-by: Hans de Goede Reviewed-by: Andy Shevchenko Cc: Signed-off-by: Jonathan Cameron --- diff --git a/drivers/iio/accel/bmc150-accel-core.c b/drivers/iio/accel/bmc150-accel-core.c index 46ab7675186cf..c526d83f14d5c 100644 --- a/drivers/iio/accel/bmc150-accel-core.c +++ b/drivers/iio/accel/bmc150-accel-core.c @@ -1805,10 +1805,7 @@ EXPORT_SYMBOL_GPL(bmc150_accel_core_probe); struct i2c_client *bmc150_get_second_device(struct i2c_client *client) { - struct bmc150_accel_data *data = i2c_get_clientdata(client); - - if (!data) - return NULL; + struct bmc150_accel_data *data = iio_priv(i2c_get_clientdata(client)); return data->second_device; } @@ -1816,10 +1813,9 @@ EXPORT_SYMBOL_GPL(bmc150_get_second_device); void bmc150_set_second_device(struct i2c_client *client) { - struct bmc150_accel_data *data = i2c_get_clientdata(client); + struct bmc150_accel_data *data = iio_priv(i2c_get_clientdata(client)); - if (data) - data->second_device = client; + data->second_device = client; } EXPORT_SYMBOL_GPL(bmc150_set_second_device);