[PATCH 1/2] ASoC: sti: Return errors from regmap_field_alloc()

[Sander Vanheule <sander@svanheule.net>]

When regmap_field_alloc() fails, it can return an error. Specifically,
it will return PTR_ERR(-ENOMEM) when the allocation returns a NULL
pointer. The code then uses these allocations with a simple NULL check:

    if (player->clk_sel) {
        // May dereference invalid pointer (-ENOMEM)
        err = regmap_field_write(player->clk_sel, ...);
    }

Ensure initialization fails by forwarding the errors from
regmap_field_alloc(), thus avoiding the use of the invalid pointers.

Fixes: 76c2145ded6b ("ASoC: sti: Add CPU DAI driver for playback")
Signed-off-by: Sander Vanheule <sander@svanheule.net>
---
 sound/soc/sti/uniperif_player.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sound/soc/sti/uniperif_player.c b/sound/soc/sti/uniperif_player.c
index 6d1ce030963c..f1b7e76f97b5 100644
--- a/sound/soc/sti/uniperif_player.c
+++ b/sound/soc/sti/uniperif_player.c
@@ -1029,7 +1029,12 @@ static int uni_player_parse_dt_audio_glue(struct platform_device *pdev,
 	}
 
 	player->clk_sel = regmap_field_alloc(regmap, regfield[0]);
+	if (IS_ERR(player->clk_sel))
+		return PTR_ERR(player->clk_sel);
+
 	player->valid_sel = regmap_field_alloc(regmap, regfield[1]);
+	if (IS_ERR(player->valid_sel))
+		return PTR_ERR(player->valid_sel);
 
 	return 0;
 }
-- 
2.53.0