All of lore.kernel.org
 help / color / mirror / Atom feed
From: gregkh@linuxfoundation.org (Greg KH)
To: linux-arm-kernel@lists.infradead.org
Subject: Kernel memory leak on CDC-ACM device plug/unplug
Date: Wed, 19 Sep 2018 22:32:22 +0200	[thread overview]
Message-ID: <20180919203222.GA1492@kroah.com> (raw)
In-Reply-To: <CAGkQfmP6o+e_nanviTfRt7Ej9U+4BdqDYvMM83FjHhSCECcH3w@mail.gmail.com>

On Wed, Sep 19, 2018 at 04:11:55PM +0200, Romain Izard wrote:
> While trying to debug a memory leak problem, I encountered the following
> problem:
> 
> After plugging/unplugging an USB CDC-ACM device, kmemleak reports multiple
> copies of the following leak. It is not necessary to open the port for the
> leak to happen.
> 
> unreferenced object 0xddbfd500 (size 128):
>   comm "kworker/0:3", pid 675, jiffies 69734 (age 916.580s)
>   hex dump (first 32 bytes):
>     01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>     00 00 00 00 00 00 00 00 00 00 00 00 1c d5 bf dd  ................
>   backtrace:
>     [<da0194da>] acm_probe+0x868/0xc3c
>     [<cc72c809>] usb_probe_interface+0x11c/0x274
>     [<bbce212c>] driver_probe_device+0x22c/0x320
>     [<544a5b43>] bus_for_each_drv+0x58/0xb8
>     [<fe5944dc>] __device_attach+0xd0/0x138
>     [<d807c1e5>] bus_probe_device+0x84/0x8c
>     [<16645f2c>] device_add+0x3cc/0x5c0
>     [<80c11c88>] usb_set_configuration+0x448/0x7b0
>     [<76bdbcdf>] generic_probe+0x2c/0x78
>     [<bbce212c>] driver_probe_device+0x22c/0x320
>     [<544a5b43>] bus_for_each_drv+0x58/0xb8
>     [<fe5944dc>] __device_attach+0xd0/0x138
>     [<d807c1e5>] bus_probe_device+0x84/0x8c
>     [<16645f2c>] device_add+0x3cc/0x5c0
>     [<02a49898>] usb_new_device+0x264/0x424
>     [<865a481b>] hub_event+0xa20/0x1154
> 
> For each additional plug/unplug cycle, around 30 such new leaks are created.
> 
> Tested on a SAMA5D2 Xplained demo board, with a v4.18.8 kernel.
> The CDC-ACM device was another SAMA5D2 device, with a composite profile
> including a CDC-ACM port implemented with configfs.

Have you come up with any patches that might resolve this?  It's hard to
see what exactly is "leaking" here.

thanks,

greg k-h

  reply	other threads:[~2018-09-19 20:32 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-19 14:11 Kernel memory leak on CDC-ACM device plug/unplug Romain Izard
2018-09-19 20:32 ` Greg KH [this message]
2018-09-20 14:17   ` Romain Izard
2018-09-21  8:08 ` Oliver Neukum
2018-09-21 10:11   ` Romain Izard

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180919203222.GA1492@kroah.com \
    --to=gregkh@linuxfoundation.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.