Re: BUG: drivers/usb/host/xhci: memleak in alloc from xhci_disable_usb3_lpm_timeout()

[Mirsad Goran Todorovac]

On 27.3.2023. 11:41, Mathias Nyman wrote:
> On 25.3.2023 13.33, Mirsad Goran Todorovac wrote:
> > On 25. 03. 2023. 12:27, Mirsad Goran Todorovac wrote:
> > > Hi all!
> > >
> > > Here are again the good news and the bad news:
> > >
> > > BAD:  another kernel memory leak detected (one more to hunt down and fix)
> > > GOOD: another kernel memory leak detected (one less unaccounted for)
> > >
> > > I tried to make some fun, but maintainers are busy folks, so let's get down
> > > to business:
> > >
> > > ---
> > > Nine (9) new systemd-udevd kernel memory leaks occurred (unable to reproduce).
> > >
> > > The platform is Ubuntu 22.10 with (relatively recent) systemd 251.4-1ubuntu7.1
> > > on LENOVO_MT_82H8_BU_idea_FM_IdeaPad 3 15ITL6 with BIOS GGCN51WW from 11/16/2022.
> > >
> > > The symptom (/sys/kernel/debug/kmemleak output):
> > >
> > > unreferenced object 0xffff909698ff9280 (size 64):
> > >    comm "systemd-udevd", pid 436, jiffies 4294893239 (age 6287.088s)
> > >    hex dump (first 32 bytes):
> > >      e0 51 bb 99 96 90 ff ff 00 00 00 00 00 00 00 00  .Q..............
> > >      40 5b bb 99 96 90 ff ff 00 00 00 00 00 00 00 00  @[..............
> > >    backtrace:
> > >      [<ffffffffb29de94c>] slab_post_alloc_hook+0x8c/0x320
> > >      [<ffffffffb29e5107>] __kmem_cache_alloc_node+0x1c7/0x2b0
> > >      [<ffffffffb2962f3b>] kmalloc_node_trace+0x2b/0xa0
> > >      [<ffffffffb31af2ec>] xhci_alloc_command+0x7c/0x1b0
> > >      [<ffffffffb31af451>] xhci_alloc_command_with_ctx+0x21/0x70
> > >      [<ffffffffb31a8a3e>] xhci_change_max_exit_latency+0x2e/0x1c0>>      [<ffffffffb31a8c5b>] 
> > > xhci_disable_usb3_lpm_timeout+0x7b/0xb0
> > >      [<ffffffffb31457a7>] usb_disable_link_state+0x57/0xe0
>
> Thanks for the report.
>
> I think I found the leak, and wrote a patch for it.
> Any chance you could test it with the same setup?
>
> https://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git/commit/?h=for-usb-linus&id=8bacee588602ed74cc22aaf4c56b796300e5a943

Hi, Mathias,

Great you have found the leak!

I cannot make testing in the same setup because I can access that particular box
until after I finish my day job.

I will prioritise it.

If this is the catch, it will save me almost a dozen bisect builds. :-)

Best regards,
Mirsad

--
Mirsad Todorovac
System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb
Republic of Croatia, the European Union

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