From 490a5a46da232392f00b9ad131ee885c11a62ce9 Mon Sep 17 00:00:00 2001 From: Zheng Wang Date: Wed, 26 Apr 2023 16:02:17 +0800 Subject: [PATCH] hwmon: (xgene) Fix use after free bug in xgene_hwmon_remove due to race condition mainline inclusion from mainline-v6.3-rc3 commit cb090e64cf25602b9adaf32d5dfc9c8bec493cd1 category: bugfix bugzilla: 188657, https://gitee.com/src-openeuler/kernel/issues/I6T36A CVE: CVE-2023-1855 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=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 Link: https://lore.kernel.org/r/20230310084007.1403388-1-zyytlz.wz@163.com Signed-off-by: Guenter Roeck Signed-off-by: Zhao Wenhui Reviewed-by: songping yu Reviewed-by: Xiu Jianfeng Reviewed-by: Zhang Qiao Reviewed-by: Chen Hui Signed-off-by: Jialin Zhang --- drivers/hwmon/xgene-hwmon.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/hwmon/xgene-hwmon.c b/drivers/hwmon/xgene-hwmon.c index f2a5af239c95..f5d3cf86753f 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) -- GitLab