From 6bdc3023d62ed5c7d591f0eb27a5adb37fb892ae Mon Sep 17 00:00:00 2001 From: David Carlier Date: Tue, 5 May 2026 14:37:48 +0100 Subject: [PATCH] iio: gyro: itg3200: fix i2c read into the wrong stack location itg3200_read_all_channels() takes `__be16 *buf' as a parameter and fills the i2c_msg destination as `(char *)&buf'. Since `buf' is the parameter (a pointer), `&buf' is the address of the local pointer slot on the stack of itg3200_read_all_channels(), not the address of the caller's scan buffer. The (char *) cast hides the type mismatch. i2c_transfer() therefore writes ITG3200_SCAN_ELEMENTS * sizeof(s16) = 8 bytes into the parameter's stack slot, which is discarded when the function returns. The caller's scan buffer in itg3200_trigger_handler() is never written to, so iio_push_to_buffers_with_timestamp() pushes uninitialised stack contents to userspace via /dev/iio:deviceX every scan -- both a functional bug (no actual gyroscope or temperature data is delivered through the triggered buffer) and an information leak. The non-buffered read_raw() path is unaffected: it goes through itg3200_read_reg_s16() which uses `&out' on a local s16 value, where that is correct. Drop the spurious `&' so the i2c read writes into the caller's buffer. Fixes: 9dbf091da080 ("iio: gyro: Add itg3200") Cc: stable@vger.kernel.org Signed-off-by: David Carlier Reviewed-by: Andy Shevchenko Signed-off-by: Jonathan Cameron --- drivers/iio/gyro/itg3200_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iio/gyro/itg3200_buffer.c b/drivers/iio/gyro/itg3200_buffer.c index cf97adfa9727..87efa2c74ca4 100644 --- a/drivers/iio/gyro/itg3200_buffer.c +++ b/drivers/iio/gyro/itg3200_buffer.c @@ -34,7 +34,7 @@ static int itg3200_read_all_channels(struct i2c_client *i2c, __be16 *buf) .addr = i2c->addr, .flags = i2c->flags | I2C_M_RD, .len = ITG3200_SCAN_ELEMENTS * sizeof(s16), - .buf = (char *)&buf, + .buf = (char *)buf, }, };