Hello Linux kernel expert:
> > From: Lianqin Hu <hulianqin@xxxxxxxx>
> >
> > Considering that in some extreme cases, when performing the unbinding
> > operation, gserial_disconnect has cleared gser->ioport, which triggers
> > gadget reconfiguration, and then calls gs_read_complete, resulting in
> > access to a null pointer. Therefore, ep is disabled before
> > gserial_disconnect sets port to null to prevent this from happening.
> >
> > Call trace:
> > gs_read_complete+0x58/0x240
> > usb_gadget_giveback_request+0x40/0x160
> > dwc3_remove_requests+0x170/0x484
> > dwc3_ep0_out_start+0xb0/0x1d4
> > __dwc3_gadget_start+0x25c/0x720
> > kretprobe_trampoline.cfi_jt+0x0/0x8
> > kretprobe_trampoline.cfi_jt+0x0/0x8
> > udc_bind_to_driver+0x1d8/0x300
> > usb_gadget_probe_driver+0xa8/0x1dc
> > gadget_dev_desc_UDC_store+0x13c/0x188
> > configfs_write_iter+0x160/0x1f4
> > vfs_write+0x2d0/0x40c
> > ksys_write+0x7c/0xf0
> > __arm64_sys_write+0x20/0x30
> > invoke_syscall+0x60/0x150
> > el0_svc_common+0x8c/0xf8
> > do_el0_svc+0x28/0xa0
> > el0_svc+0x24/0x84
> >
> > Fixes: c1dca562be8a ("usb gadget: split out serial core")
> > Cc: stable@xxxxxxxxxxxxxxx
> >
> > Suggested-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Lianqin Hu <hulianqin@xxxxxxxx>
> >
> > v2:
> > - Remove some address information from patch descriptions
> > - Link to v1:
> > https://apc01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore
> > .kernel.org%2Fall%2FTYUPR06MB621763AB815989161F4033AFD2762%40TY
> UPR06MB
> > - Link to suggestions:
> > https://apc01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore
> > .kernel.org%2Fall%2FTYUPR06MB6217DE28012FFEC5E808DD64D2962%40TY
> UPR06MB
>
> The "v2:" needs to go below the --- line, what happened to that?
OK, I'll modify it.
> And no need to have a blank line after the cc: stable, right? Did you run
> checkpatch.pl on this?
Sorry, I didn't check it carefully enough. I will modify it and send a new patch.
Run checkpatch.pl before sending the patch:
root@vivo-600-G6:~/linux_kernel/linux# ./scripts/checkpatch.pl 0001-usb-gadget-u_serial-Disable-ep-before-setting-port-t.patch
total: 0 errors, 0 warnings, 20 lines checked
Thanks
