From 077bfdfb6de9b2ac61913741e355a154215231d2 Mon Sep 17 00:00:00 2001 From: Zheng Wang Date: Wed, 28 Jun 2023 14:19:08 +0800 Subject: [PATCH] usb: gadget: udc: renesas_usb3: Fix use after free bug in renesas_usb3_remove due to race condition mainline inclusion from mainline-v6.4-rc1 commit 2b947f8769be8b8181dc795fd292d3e7120f5204 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I7EDYS CVE: CVE-2023-35828 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2b947f8769be8b8181dc795fd292d3e7120f5204 -------------------------------- In renesas_usb3_probe, role_work is bound with renesas_usb3_role_work. renesas_usb3_start will be called to start the work. If we remove the driver which will call usbhs_remove, there may be an unfinished work. The possible sequence is as follows: CPU0 CPU1 renesas_usb3_role_work renesas_usb3_remove usb_role_switch_unregister device_unregister kfree(sw) //free usb3->role_sw usb_role_switch_set_role //use usb3->role_sw The usb3->role_sw could be freed under such circumstance and then used in usb_role_switch_set_role. This bug was found by static analysis. And note that removing a driver is a root-only operation, and should never happen in normal case. But the root user may directly remove the device which will also trigger the remove function. Fix it by canceling the work before cleanup in the renesas_usb3_remove. Fixes: 39facfa01c9f ("usb: gadget: udc: renesas_usb3: Add register of usb role switch") Signed-off-by: Zheng Wang Reviewed-by: Yoshihiro Shimoda Link: https://lore.kernel.org/r/20230320062931.505170-1-zyytlz.wz@163.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Jialin Zhang (cherry picked from commit c6acce6af8e3a3e27aacd9135b2f1a169ac7d461) --- drivers/usb/gadget/udc/renesas_usb3.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/usb/gadget/udc/renesas_usb3.c b/drivers/usb/gadget/udc/renesas_usb3.c index 601829a6b4ba..a10f41c4a3f2 100644 --- a/drivers/usb/gadget/udc/renesas_usb3.c +++ b/drivers/usb/gadget/udc/renesas_usb3.c @@ -2568,6 +2568,7 @@ static int renesas_usb3_remove(struct platform_device *pdev) debugfs_remove_recursive(usb3->dentry); device_remove_file(&pdev->dev, &dev_attr_role); + cancel_work_sync(&usb3->role_work); usb_role_switch_unregister(usb3->role_sw); usb_del_gadget_udc(&usb3->gadget); -- GitLab