From: Jia-Ju Bai baijiaju1990@gmail.com
[ Upstream commit 9c1ed62ae0690dfe5d5e31d8f70e70a95cb48e52 ]
The driver may sleep while holding a spinlock. The function call path (from bottom to top) in Linux 4.19 is:
drivers/usb/gadget/udc/core.c, 1175: kzalloc(GFP_KERNEL) in usb_add_gadget_udc_release drivers/usb/gadget/udc/core.c, 1272: usb_add_gadget_udc_release in usb_add_gadget_udc drivers/usb/gadget/udc/gr_udc.c, 2186: usb_add_gadget_udc in gr_probe drivers/usb/gadget/udc/gr_udc.c, 2183: spin_lock in gr_probe
drivers/usb/gadget/udc/core.c, 1195: mutex_lock in usb_add_gadget_udc_release drivers/usb/gadget/udc/core.c, 1272: usb_add_gadget_udc_release in usb_add_gadget_udc drivers/usb/gadget/udc/gr_udc.c, 2186: usb_add_gadget_udc in gr_probe drivers/usb/gadget/udc/gr_udc.c, 2183: spin_lock in gr_probe
drivers/usb/gadget/udc/gr_udc.c, 212: debugfs_create_file in gr_probe drivers/usb/gadget/udc/gr_udc.c, 2197: gr_dfs_create in gr_probe drivers/usb/gadget/udc/gr_udc.c, 2183: spin_lock in gr_probe
drivers/usb/gadget/udc/gr_udc.c, 2114: devm_request_threaded_irq in gr_request_irq drivers/usb/gadget/udc/gr_udc.c, 2202: gr_request_irq in gr_probe drivers/usb/gadget/udc/gr_udc.c, 2183: spin_lock in gr_probe
kzalloc(GFP_KERNEL), mutex_lock(), debugfs_create_file() and devm_request_threaded_irq() can sleep at runtime.
To fix these possible bugs, usb_add_gadget_udc(), gr_dfs_create() and gr_request_irq() are called without handling the spinlock.
These bugs are found by a static analysis tool STCheck written by myself.
Signed-off-by: Jia-Ju Bai baijiaju1990@gmail.com Signed-off-by: Felipe Balbi balbi@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/gadget/udc/gr_udc.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/gadget/udc/gr_udc.c b/drivers/usb/gadget/udc/gr_udc.c index 1f9941145746e..feb73a1c42ef9 100644 --- a/drivers/usb/gadget/udc/gr_udc.c +++ b/drivers/usb/gadget/udc/gr_udc.c @@ -2200,8 +2200,6 @@ static int gr_probe(struct platform_device *pdev) return -ENOMEM; }
- spin_lock(&dev->lock); - /* Inside lock so that no gadget can use this udc until probe is done */ retval = usb_add_gadget_udc(dev->dev, &dev->gadget); if (retval) { @@ -2210,15 +2208,21 @@ static int gr_probe(struct platform_device *pdev) } dev->added = 1;
+ spin_lock(&dev->lock); + retval = gr_udc_init(dev); - if (retval) + if (retval) { + spin_unlock(&dev->lock); goto out; - - gr_dfs_create(dev); + }
/* Clear all interrupt enables that might be left on since last boot */ gr_disable_interrupts_and_pullup(dev);
+ spin_unlock(&dev->lock); + + gr_dfs_create(dev); + retval = gr_request_irq(dev, dev->irq); if (retval) { dev_err(dev->dev, "Failed to request irq %d\n", dev->irq); @@ -2247,8 +2251,6 @@ static int gr_probe(struct platform_device *pdev) dev_info(dev->dev, "regs: %p, irq %d\n", dev->regs, dev->irq);
out: - spin_unlock(&dev->lock); - if (retval) gr_remove(pdev);