From 6946c726c3f4c36f0f049e6f97e88c510b15f65d Mon Sep 17 00:00:00 2001 From: Junrui Luo Date: Wed, 10 Dec 2025 17:48:08 +0800 Subject: [PATCH] hwmon: (ibmpex) fix use-after-free in high/low store The ibmpex_high_low_store() function retrieves driver data using dev_get_drvdata() and uses it without validation. This creates a race condition where the sysfs callback can be invoked after the data structure is freed, leading to use-after-free. Fix by adding a NULL check after dev_get_drvdata(), and reordering operations in the deletion path to prevent TOCTOU. Reported-by: Yuhao Jiang Reported-by: Junrui Luo Fixes: 57c7c3a0fdea ("hwmon: IBM power meter driver") Signed-off-by: Junrui Luo Link: https://lore.kernel.org/r/MEYPR01MB7886BE2F51BFE41875B74B60AFA0A@MEYPR01MB7886.ausprd01.prod.outlook.com Signed-off-by: Guenter Roeck --- drivers/hwmon/ibmpex.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/hwmon/ibmpex.c b/drivers/hwmon/ibmpex.c index 228c5f6c6f383..129f3a9e8fe96 100644 --- a/drivers/hwmon/ibmpex.c +++ b/drivers/hwmon/ibmpex.c @@ -277,6 +277,9 @@ static ssize_t ibmpex_high_low_store(struct device *dev, { struct ibmpex_bmc_data *data = dev_get_drvdata(dev); + if (!data) + return -ENODEV; + ibmpex_reset_high_low_data(data); return count; @@ -508,6 +511,9 @@ static void ibmpex_bmc_delete(struct ibmpex_bmc_data *data) { int i, j; + hwmon_device_unregister(data->hwmon_dev); + dev_set_drvdata(data->bmc_device, NULL); + device_remove_file(data->bmc_device, &sensor_dev_attr_reset_high_low.dev_attr); device_remove_file(data->bmc_device, &dev_attr_name.attr); @@ -521,8 +527,7 @@ static void ibmpex_bmc_delete(struct ibmpex_bmc_data *data) } list_del(&data->list); - dev_set_drvdata(data->bmc_device, NULL); - hwmon_device_unregister(data->hwmon_dev); + ipmi_destroy_user(data->user); kfree(data->sensors); kfree(data); -- 2.47.3