6.1-stable review patch. If anyone has any objections, please let me know.
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From: Duoming Zhou duoming@zju.edu.cn
commit 41ca62e3e21e48c2903b3b45e232cf4f2ff7434f upstream.
The delayed work item otg_event is initialized in fsl_otg_conf() and scheduled under two conditions: 1. When a host controller binds to the OTG controller. 2. When the USB ID pin state changes (cable insertion/removal).
A race condition occurs when the device is removed via fsl_otg_remove(): the fsl_otg instance may be freed while the delayed work is still pending or executing. This leads to use-after-free when the work function fsl_otg_event() accesses the already freed memory.
The problematic scenario:
(detach thread) | (delayed work) fsl_otg_remove() | kfree(fsl_otg_dev) //FREE| fsl_otg_event() | og = container_of(...) //USE | og-> //USE
Fix this by calling disable_delayed_work_sync() in fsl_otg_remove() before deallocating the fsl_otg structure. This ensures the delayed work is properly canceled and completes execution prior to memory deallocation.
This bug was identified through static analysis.
Fixes: 0807c500a1a6 ("USB: add Freescale USB OTG Transceiver driver") Cc: stable stable@kernel.org Signed-off-by: Duoming Zhou duoming@zju.edu.cn Link: https://patch.msgid.link/20251205034831.12846-1-duoming@zju.edu.cn Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/phy/phy-fsl-usb.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/usb/phy/phy-fsl-usb.c +++ b/drivers/usb/phy/phy-fsl-usb.c @@ -987,6 +987,7 @@ static int fsl_otg_remove(struct platfor { struct fsl_usb2_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ disable_delayed_work_sync(&fsl_otg_dev->otg_event); usb_remove_phy(&fsl_otg_dev->phy); free_irq(fsl_otg_dev->irq, fsl_otg_dev);