[PATCH] iio: avoid fortify-string overflow error

[Arnd Bergmann]

From: Arnd Bergmann <arnd@xxxxxxxx>

The memcpy() call in dlhl60d.c triggers a check with clang-19:

In file included from drivers/iio/pressure/dlhl60d.c:11:
In file included from include/linux/module.h:17:
include/linux/fortify-string.h:553:4: error: call to '__write_overflow_field' declared with 'warning' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror,-Wattribute-warning]
  553 |                         __write_overflow_field(p_size_field, size);
      |                         ^

It writes into a two member array from a loop over a linked list
that likely has some indication of having more than two entries.

Add a conditional check there to avoid the overflow.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 drivers/iio/pressure/dlhl60d.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/iio/pressure/dlhl60d.c b/drivers/iio/pressure/dlhl60d.c
index 28c8269ba65d..a43ecda849db 100644
--- a/drivers/iio/pressure/dlhl60d.c
+++ b/drivers/iio/pressure/dlhl60d.c
@@ -262,6 +262,8 @@ static irqreturn_t dlh_trigger_handler(int irq, void *private)
 			&st->rx_buf[1] + chn * DLH_NUM_DATA_BYTES,
 			DLH_NUM_DATA_BYTES);
 		i++;
+		if (i >= ARRAY_SIZE(tmp_buf))
+			break;
 	}
 
 	iio_push_to_buffers(indio_dev, tmp_buf);
-- 
2.39.2