Chunfeng Yun
26ca30516b
[ Upstream commitd28f4091ea] When handle qmu transfer irq, it will unlock @mtu->lock before give back request, if another thread handle disconnect event at the same time, and try to disable ep, it may lock @mtu->lock and free qmu ring, then qmu irq hanlder may get a NULL gpd, avoid the KE by checking gpd's value before handling it. e.g. qmu done irq on cpu0 thread running on cpu1 qmu_done_tx() handle gpd [0] mtu3_requ_complete() mtu3_gadget_ep_disable() unlock @mtu->lock give back request lock @mtu->lock mtu3_ep_disable() mtu3_gpd_ring_free() unlock @mtu->lock lock @mtu->lock get next gpd [1] [1]: goto [0] to handle next gpd, and next gpd may be NULL. Fixes:48e0d3735a("usb: mtu3: supports new QMU format") Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com> Link: https://lore.kernel.org/r/20230417025203.18097-3-chunfeng.yun@mediatek.com 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.