iio: imu: st_lsm6dsx: fix possible lockup in st_lsm6dsx_read_fifo

Prevent st_lsm6dsx_read_fifo from falling in an infinite loop in case
pattern_len is equal to zero and the device FIFO is not empty.

Fixes: 290a6ce11d93 ("iio: imu: add support to lsm6dsx driver")
Signed-off-by: Silvano Seva <s.seva@4sigma.it>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20250311085030.3593-2-s.seva@4sigma.it
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
index 0a7cd8c1aa3313a113b9092d6a58d597ba68290c..480a9b31065cd3b62508ed8c1f2ed4cdd779eb52 100644 (file)
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
@@ -392,6 +392,9 @@ int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw)
        if (fifo_status & cpu_to_le16(ST_LSM6DSX_FIFO_EMPTY_MASK))
                return 0;
 
+       if (!pattern_len)
+               pattern_len = ST_LSM6DSX_SAMPLE_SIZE;
+
        fifo_len = (le16_to_cpu(fifo_status) & fifo_diff_mask) *
                   ST_LSM6DSX_CHAN_SIZE;
        fifo_len = (fifo_len / pattern_len) * pattern_len;