From: Eli Billauer <eli.billauer@gmail.com>
To: Ziyang Xuan <william.xuanziyang@huawei.com>
Cc: arnd@arndb.de, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] char: xillybus: fix msg_ep UAF in xillyusb_probe()
Date: Sat, 16 Oct 2021 18:43:43 +0300 [thread overview]
Message-ID: <616AF32F.1070403@gmail.com> (raw)
In-Reply-To: <20211016052047.1611983-1-william.xuanziyang@huawei.com>
Correct. Thanks a lot.
Acked-by: Eli Billauer <eli.billauer@gmail.com>
On 16/10/21 08:20, Ziyang Xuan wrote:
> When endpoint_alloc() return failed in xillyusb_setup_base_eps(),
> 'xdev->msg_ep' will be freed but not set to NULL. That lets program
> enter fail handling to cleanup_dev() in xillyusb_probe(). Check for
> 'xdev->msg_ep' is invalid in cleanup_dev() because 'xdev->msg_ep' did
> not set to NULL when was freed. So the UAF problem for 'xdev->msg_ep'
> is triggered.
>
> ==================================================================
> BUG: KASAN: use-after-free in fifo_mem_release+0x1f4/0x210
> CPU: 0 PID: 166 Comm: kworker/0:2 Not tainted 5.15.0-rc5+ #19
> Call Trace:
> dump_stack_lvl+0xe2/0x152
> print_address_description.constprop.0+0x21/0x140
> ? fifo_mem_release+0x1f4/0x210
> kasan_report.cold+0x7f/0x11b
> ? xillyusb_probe+0x530/0x700
> ? fifo_mem_release+0x1f4/0x210
> fifo_mem_release+0x1f4/0x210
> ? __sanitizer_cov_trace_pc+0x1d/0x50
> endpoint_dealloc+0x35/0x2b0
> cleanup_dev+0x90/0x120
> xillyusb_probe+0x59a/0x700
> ...
>
> Freed by task 166:
> kasan_save_stack+0x1b/0x40
> kasan_set_track+0x1c/0x30
> kasan_set_free_info+0x20/0x30
> __kasan_slab_free+0x109/0x140
> kfree+0x117/0x4c0
> xillyusb_probe+0x606/0x700
>
> Set 'xdev->msg_ep' to NULL after being freed in xillyusb_setup_base_eps()
> to fix the UAF problem.
>
> Fixes: a53d1202aef1 ("char: xillybus: Add driver for XillyUSB (Xillybus variant for USB)")
> Signed-off-by: Ziyang Xuan<william.xuanziyang@huawei.com>
> ---
> drivers/char/xillybus/xillyusb.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/char/xillybus/xillyusb.c b/drivers/char/xillybus/xillyusb.c
> index e7f88f35c702..dc3551796e5e 100644
> --- a/drivers/char/xillybus/xillyusb.c
> +++ b/drivers/char/xillybus/xillyusb.c
> @@ -1912,6 +1912,7 @@ static int xillyusb_setup_base_eps(struct xillyusb_dev *xdev)
>
> dealloc:
> endpoint_dealloc(xdev->msg_ep); /* Also frees FIFO mem if allocated */
> + xdev->msg_ep = NULL;
> return -ENOMEM;
> }
>
>
prev parent reply other threads:[~2021-10-16 15:44 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-16 5:20 [PATCH] char: xillybus: fix msg_ep UAF in xillyusb_probe() Ziyang Xuan
2021-10-16 15:43 ` Eli Billauer [this message]
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=616AF32F.1070403@gmail.com \
--to=eli.billauer@gmail.com \
--cc=arnd@arndb.de \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=william.xuanziyang@huawei.com \
/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