From: Hyunwoo Kim <imv4bel@gmail.com>
To: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "Arnd Bergmann" <arnd@arndb.de>,
laforge@gnumonks.org,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>,
linux-kernel@vger.kernel.org,
"Paul Fulghum" <paulkf@microgate.com>,
akpm@osdl.org, "Lubomir Rintel" <lkundrak@v3.sk>,
imv4bel@gmail.com
Subject: Re: [PATCH] pcmcia: synclink_cs: Fix use-after-free in mgslpc_ioctl()
Date: Thu, 15 Sep 2022 22:03:33 -0700 [thread overview]
Message-ID: <20220916050333.GA188358@ubuntu> (raw)
In-Reply-To: <YyLcG1hG5d6D4zNN@owl.dominikbrodowski.net>
The previous mailing list is here:
https://lore.kernel.org/lkml/20220913052020.GA85241@ubuntu/#r
Dear all,
I reported that the scr24x_cs driver does not cause UAF, which is incorrect.
UAFs can also occur in the scr24x_cs driver in the following order:
```
cpu0 cpu1
1. open()
2. scr24x_remove()
device_destroy()
cdev_del()
kref_put()
3. scr24x_open()
kref_get() <- refcount_t: addition on 0;
4. scr24x_delete()
kfree(dev);
5. scr24x_read() <- UAF
```
Because this driver uses kref_init, it looks as if no UAF is happening, but it does.
Since there is no lock between .open and .remove, kref_get() is called after kref_put()
is called, so "refcount_t: addition on 0;" This is what happens.
So I submitted a patch for all drivers in this path:
- synclink_cs.c "v2" patch : https://lore.kernel.org/lkml/20220916045734.GA187909@ubuntu/T/#u
- cm4040_cs.c : https://lore.kernel.org/lkml/20220916045834.GA188033@ubuntu/T/#u
- cm4000_cs.c : https://lore.kernel.org/lkml/20220916045929.GA188153@ubuntu/T/#u
- scr24x_cs.c : https://lore.kernel.org/lkml/20220916050006.GA188273@ubuntu/T/#u
Best Regards,
Hyunwoo Kim.
next prev parent reply other threads:[~2022-09-16 5:03 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-13 5:20 [PATCH] pcmcia: synclink_cs: Fix use-after-free in mgslpc_ioctl() Hyunwoo Kim
2022-09-13 14:59 ` Arnd Bergmann
2022-09-13 15:14 ` Paul Fulghum
2022-09-13 15:43 ` Hyunwoo Kim
2022-09-15 2:08 ` Hyunwoo Kim
2022-09-15 7:35 ` Arnd Bergmann
2022-09-15 8:02 ` Dominik Brodowski
2022-09-15 9:00 ` Hyunwoo Kim
2022-09-16 5:03 ` Hyunwoo Kim [this message]
2022-09-15 14:05 ` Harald Welte
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