From: Johannes Weiner <hannes@cmpxchg.org>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Oliver Neukum <oliver@neukum.name>,
linux-kernel@vger.kernel.org, stable@kernel.org
Subject: Re: [patch] hiddev: fix incorrect hiddev freeing
Date: Mon, 9 Mar 2009 03:38:02 +0100 [thread overview]
Message-ID: <20090309023802.GA11709@cmpxchg.org> (raw)
In-Reply-To: <20090309023151.GA11464@cmpxchg.org>
On Mon, Mar 09, 2009 at 03:31:51AM +0100, Johannes Weiner wrote:
> When hiddev_open() fails for whatever reason, free the just allocated
> hiddev_list structure shared hiddev potentially still in use.
^
instead of
Sorry, it's late (or early?) Need a resend?
> The hiddev is freed in device disconnect/last close of the device file
> and must not be freed while there are possibly existing references to
> it.
>
> This is probably responsible for these
>
> http://kerneloops.org/oops.php?number=221185
> http://kerneloops.org/oops.php?number=220365
>
> where a reader sleeps on the waitqueue, the device gets disconnected
> (exist -> 0) another user tries to open it, fails on the exist check
> and frees the hiddev from the table. The finish_wait() in the reader
> will then dereference the hiddev to get to the waitqueue and oopses.
>
> This was introduced by commit 079034073faf974973baa0256b029451f6e768ad
> "HID: hiddev cleanup -- handle all error conditions properly".
>
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Oliver Neukum <oliver@neukum.name>
> ---
>
> diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
> index 4940e4d..00ea1ed 100644
> --- a/drivers/hid/usbhid/hiddev.c
> +++ b/drivers/hid/usbhid/hiddev.c
> @@ -306,7 +306,7 @@ static int hiddev_open(struct inode *inode, struct file *file)
> return 0;
> bail:
> file->private_data = NULL;
> - kfree(list->hiddev);
> + kfree(list);
> return res;
> }
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
next prev parent reply other threads:[~2009-03-09 2:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-09 2:31 [patch] hiddev: fix incorrect hiddev freeing Johannes Weiner
2009-03-09 2:38 ` Johannes Weiner [this message]
2009-03-09 22:37 ` Johannes Weiner
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=20090309023802.GA11709@cmpxchg.org \
--to=hannes@cmpxchg.org \
--cc=jkosina@suse.cz \
--cc=linux-kernel@vger.kernel.org \
--cc=oliver@neukum.name \
--cc=stable@kernel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox