On Thu, Jun 10, 2021 at 10:00:47AM +0800, Peter Chen wrote:

On 21-06-09 11:42:53, Greg Kroah-Hartman wrote:

quoted

On Wed, Jun 09, 2021 at 11:01:07AM +0200, Greg Kroah-Hartman wrote:

quoted

On Tue, Jun 08, 2021 at 09:50:01AM -0700, Jack Pham wrote:

quoted

Hi Peter,

On Tue, Jun 08, 2021 at 06:56:56PM +0800, Peter Chen wrote:

quoted

When do system reboot, it calls dwc3_shutdown and the whole debugfs
for dwc3 has removed first, when the gadget tries to do deinit, and
remove debugfs for its endpoints, it meets NULL pointer dereference
issue when call debugfs_lookup. Fix it by removing the whole dwc3
debugfs later than dwc3_drd_exit.

Ouch, thanks for catching this! I think in your previous reply[1] you
did warn about the debugfs_remove_recursive() getting called twice, but
it seems here the issue is due to the debugfs_lookup() getting called on
a stale dwc->root pointer after it was already removed.

We can also fix this by getting rid of that "root" pointer as it's
useless (we can look it up if we need it.)  I'll send a patch later to
do that, as it's a good idea to do anyway, and is independant of this
fix.

Now sent:
	https://lore.kernel.org/r/20210609093924.3293230-1-gregkh@linuxfoundation.org (local)

Hi Felipe,

With Greg above patch, this issue is fixed indirectly. I don't think my patch is
needed, do you think so?

Which patch is "your patch" here?

thanks,

greg k-h