From c9d8e9adaa63150ef7e833480b799d0bab83a276 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 9 Apr 2026 15:40:48 +0200 Subject: [PATCH] iio: imu: st_lsm6dsx: fix stack leak in tagged FIFO buffer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The tagged FIFO path declares iio_buff on the stack with __aligned(8) but no initializer, but there is a hole in the structure, which will then leak to userspace as ST_LSM6DSX_SAMPLE_SIZE bytes (6) will be copied, but the space between that and the timestamp are not initialized. Commit c14edb4d0bdc ("iio:imu:st_lsm6dsx Fix alignment and data leak issues") moved the untagged FIFO path to a kzalloc'd buffer in hw->scan, but for the tagged path it only added the alignment qualifier and not the initializer :( Fix this by just zero-initializing the structure on the stack. Cc: Lorenzo Bianconi Cc: Jonathan Cameron Cc: David Lechner Cc: "Nuno Sá" Cc: Andy Shevchenko Fixes: c14edb4d0bdc ("iio:imu:st_lsm6dsx Fix alignment and data leak issues") Cc: stable Assisted-by: gregkh_clanker_t1000 Signed-off-by: Greg Kroah-Hartman Reviewed-by: David Lechner Signed-off-by: Jonathan Cameron --- drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c index 5b28a3ffcc3d..48291203d1cd 100644 --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c @@ -609,7 +609,7 @@ int st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw *hw) * must be passed a buffer that is aligned to 8 bytes so * as to allow insertion of a naturally aligned timestamp. */ - u8 iio_buff[ST_LSM6DSX_IIO_BUFF_SIZE] __aligned(8); + u8 iio_buff[ST_LSM6DSX_IIO_BUFF_SIZE] __aligned(8) = { }; u8 tag; bool reset_ts = false; int i, err, read_len;