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
next prev parent 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$(echo .)org \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox