diff options
| author | Jia-Ju Bai <baijiaju1990@gmail.com> | 2019-12-18 11:43:49 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-28 15:42:20 +0100 |
| commit | 8efbca5ac9070a9d954825b9efa90fbfd3bc6ba5 (patch) | |
| tree | 8e1c3cf06eff7a51e0d1e24b1e0e00d7bf31cb9f /drivers/usb | |
| parent | b77fa964ecb1d72a671234f5bea95b41f77c233a (diff) | |
usb: gadget: udc: fix possible sleep-in-atomic-context bugs in gr_probe()
[ 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>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/gadget/udc/gr_udc.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/drivers/usb/gadget/udc/gr_udc.c b/drivers/usb/gadget/udc/gr_udc.c index 39b7136d31d9..9e246d2e55ca 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); |