gpio: aggregator: fix a potential use-after-free

On error we free aggr->lookups->dev_id before removing the entry from
the lookup table. If a concurrent thread calls gpiod_find() before we
remove the entry, it could iterate over the list and call
gpiod_match_lookup_table() which unconditionally dereferences dev_id
when calling strcmp(). Reverse the order of cleanup.

Fixes: 86f162e73d2d ("gpio: aggregator: introduce basic configfs interface")
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260520084911.27938-1-bartosz.golaszewski@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
index 5915209e1e2168b0932de4d16aff38074b889c2b..b53230065f50ec20687cd96f354fe15802271b24 100644 (file)
--- a/drivers/gpio/gpio-aggregator.c
+++ b/drivers/gpio/gpio-aggregator.c
@@ -979,8 +979,8 @@ static int gpio_aggregator_activate(struct gpio_aggregator *aggr)
 err_unregister_pdev:
        platform_device_unregister(pdev);
 err_remove_lookup_table:
-       kfree(aggr->lookups->dev_id);
        gpiod_remove_lookup_table(aggr->lookups);
+       kfree(aggr->lookups->dev_id);
 err_remove_swnode:
        fwnode_remove_software_node(swnode);
 err_remove_lookups: