iio: imu: st_lsm6dsx: fix possible lockup in st_lsm6dsx_read_tagged_fifo

commit 8114ef86e2058e2554111b793596f17bee23fa15 upstream.

Prevent st_lsm6dsx_read_tagged_fifo from falling in an infinite loop in
case pattern_len is equal to zero and the device FIFO is not empty.

Fixes: 801a6e0af0c6 ("iio: imu: st_lsm6dsx: add support to LSM6DSO")
Signed-off-by: Silvano Seva <s.seva@4sigma.it>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20250311085030.3593-4-s.seva@4sigma.it
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
index 12c728bf55ece4425c4f41d67f4a015b483459e8..2e6c634c56c7e876f2e8444743dececdd50133dc 100644 (file)
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
@@ -589,6 +589,9 @@ int st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw *hw)
        if (!fifo_len)
                return 0;
 
+       if (!pattern_len)
+               pattern_len = ST_LSM6DSX_TAGGED_SAMPLE_SIZE;
+
        for (read_len = 0; read_len < fifo_len; read_len += pattern_len) {
                err = st_lsm6dsx_read_block(hw,
                                            ST_LSM6DSX_REG_FIFO_OUT_TAG_ADDR,