This is a note to let you know that I've just added the patch titled hwmon: (xgene) Fix use after free bug in xgene_hwmon_remove due to race condition to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: hwmon-xgene-fix-use-after-free-bug-in-xgene_hwmon_re.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 643b304b873869b1b9fba66781382b215f08a5d6 Author: Zheng Wang <zyytlz.wz@xxxxxxx> Date: Fri Mar 10 16:40:07 2023 +0800 hwmon: (xgene) Fix use after free bug in xgene_hwmon_remove due to race condition [ Upstream commit cb090e64cf25602b9adaf32d5dfc9c8bec493cd1 ] In xgene_hwmon_probe, &ctx->workq is bound with xgene_hwmon_evt_work. Then it will be started. If we remove the driver which will call xgene_hwmon_remove to clean up, there may be unfinished work. The possible sequence is as follows: Fix it by finishing the work before cleanup in xgene_hwmon_remove. CPU0 CPU1 |xgene_hwmon_evt_work xgene_hwmon_remove | kfifo_free(&ctx->async_msg_fifo);| | |kfifo_out_spinlocked |//use &ctx->async_msg_fifo Fixes: 2ca492e22cb7 ("hwmon: (xgene) Fix crash when alarm occurs before driver probe") Signed-off-by: Zheng Wang <zyytlz.wz@xxxxxxx> Link: https://lore.kernel.org/r/20230310084007.1403388-1-zyytlz.wz@xxxxxxx Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/hwmon/xgene-hwmon.c b/drivers/hwmon/xgene-hwmon.c index 382ef0395d8ee..a64f768bf1818 100644 --- a/drivers/hwmon/xgene-hwmon.c +++ b/drivers/hwmon/xgene-hwmon.c @@ -768,6 +768,7 @@ static int xgene_hwmon_remove(struct platform_device *pdev) { struct xgene_hwmon_dev *ctx = platform_get_drvdata(pdev); + cancel_work_sync(&ctx->workq); hwmon_device_unregister(ctx->hwmon_dev); kfifo_free(&ctx->async_msg_fifo); if (acpi_disabled)