ASoC: sti: Return errors from regmap_field_alloc()

[ Upstream commit 272aabe ]

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: 76c2145 ("ASoC: sti: Add CPU DAI driver for playback")
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Link: https://patch.msgid.link/20260220152634.480766-2-sander@svanheule.net
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: svanheule

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;
 }