Re: [PATCH] xhci: solve a double free problem while doing s4

[Zhangjiantao (Kirin, nanjing)]

On 2021/6/11 3:27, Mathias Nyman wrote:
> On 10.6.2021 17.01, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
> > On Thu, Jun 10, 2021 at 04:45:54PM +0300, Mathias Nyman wrote:
> > > On 9.6.2021 17.22, Zhangjiantao (Kirin, nanjing) wrote:
> > > > when system is doing s4, the process of xhci_resume may be as below:
> > > > 1、xhci_mem_cleanup
> > > > 2、xhci_init->xhci_mem_init->xhci_mem_cleanup(when memory is not enough).
> > > > xhci_mem_cleanup will be executed twice when system is out of memory.
> > > > xhci->port_caps is freed in xhci_mem_cleanup,but it isn't set to NULL.
> > > > It will be freed twice when xhci_mem_cleanup is called the second time.
> > > Thanks, nice catch
> > >
> > > > We got following bug when system resumes from s4:
> > > >
> > > > kernel BUG at mm/slub.c:309!
> > > > Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
> > > > CPU: 0 PID: 5929 Tainted: G S   W   5.4.96-arm64-desktop #1
> > > > pc : __slab_free+0x5c/0x424
> > > > lr : kfree+0x30c/0x32c
> > > >
> > > > Call trace:
> > > >   __slab_free+0x5c/0x424
> > > >   kfree+0x30c/0x32c
> > > >   xhci_mem_cleanup+0x394/0x3cc
> > > >   xhci_mem_init+0x9ac/0x1070
> > > >   xhci_init+0x8c/0x1d0
> > > >   xhci_resume+0x1cc/0x5fc
> > > >   xhci_plat_resume+0x64/0x70
> > > >   platform_pm_thaw+0x28/0x60
> > > >   dpm_run_callback+0x54/0x24c
> > > >   device_resume+0xd0/0x200
> > > >   async_resume+0x24/0x60
> > > >   async_run_entry_fn+0x44/0x110
> > > >   process_one_work+0x1f0/0x490
> > > >   worker_thread+0x5c/0x450
> > > >   kthread+0x158/0x160
> > > >   ret_from_fork+0x10/0x24
> > > >
> > > > Signed-off-by: Tao Xue <xuetao09@xxxxxxxxxx>
> > > Checkpatch complains:
> > > ERROR: Missing Signed-off-by: line by nominal patch author 'Zhangjiantao (Kirin, nanjing) <water.zhangjiantao@xxxxxxxxxx>'
> > >
> > > Is Zhangjiantao (Kirin, nanjing)  the correct author? If yes can I add
> > > "Signed-off-by: Zhangjiantao (Kirin, nanjing) <water.zhangjiantao@xxxxxxxxxx>?
> > Please note that it is generally a bad thing for others to add someone
> > else's s-o-b line, as it is a legal agreement.  It is best for them to
> > send it instead.
> Good point.
> Zhangjiantao (Kirin, nanjing), could you resend with Author/Signed-off-by corrected.

Yes, I amd  and  Tao Xue are both the correct author, I will resend soon;

Thanks

--Zhangjiantao