Jia-Ju Bai
2cea5895b6
[ Upstream commit 9c1ed62ae0 ]
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>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.