iio: adc: ad7124: fix possible OOB array access

Reorder the channel bounds check before using it to index into the
channels array in ad7124_release_config_slot(). This prevents reading
past the end of the array.

The value read from invalid memory was not used, so this was mostly
harmless, but we still should not be reading out of bounds in the first
place.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-iio/aPi6V-hcaKReSNWK@stanley.mountain/
Fixes: 9065197e0d ("iio: adc: ad7124: change setup reg allocation strategy")
Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
David Lechner
2025-10-22 10:15:05 -05:00
committed by Jonathan Cameron
parent c6763b15c4
commit 97289f6acc

View File

@@ -586,13 +586,18 @@ static int ad7124_request_config_slot(struct ad7124_state *st, u8 channel)
static void ad7124_release_config_slot(struct ad7124_state *st, u8 channel)
{
unsigned int slot = st->channels[channel].cfg.cfg_slot;
unsigned int slot;
/*
* All of these conditions can happen at probe when all channels are
* disabled. Otherwise, they should not happen normally.
* All of these early return conditions can happen at probe when all
* channels are disabled. Otherwise, they should not happen normally.
*/
if (channel >= st->num_channels || slot == AD7124_CFG_SLOT_UNASSIGNED ||
if (channel >= st->num_channels)
return;
slot = st->channels[channel].cfg.cfg_slot;
if (slot == AD7124_CFG_SLOT_UNASSIGNED ||
st->cfg_slot_use_count[slot] == 0)
return;