From: Greg KH <gregkh@linuxfoundation.org>
To: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Cc: stable@vger.kernel.org, sashal@kernel.org,
Eddie Hung <eddie.hung@mediatek.com>,
Macpaul Lin <macpaul.lin@mediatek.com>,
Peter Chen <peter.chen@nxp.com>
Subject: Re: [RFC/PATCH for 4.4.y] usb: gadget: configfs: Fix use-after-free issue with udc_name
Date: Mon, 27 Dec 2021 13:47:35 +0100 [thread overview]
Message-ID: <Ycm151MQzlAC0tC3@kroah.com> (raw)
In-Reply-To: <20211223052626.1631331-1-nobuhiro1.iwamatsu@toshiba.co.jp>
On Thu, Dec 23, 2021 at 02:26:26PM +0900, Nobuhiro Iwamatsu wrote:
> From: Eddie Hung <eddie.hung@mediatek.com>
>
> commit 64e6bbfff52db4bf6785fab9cffab850b2de6870 upstream.
>
> There is a use-after-free issue, if access udc_name
> in function gadget_dev_desc_UDC_store after another context
> free udc_name in function unregister_gadget.
>
> Context 1:
> gadget_dev_desc_UDC_store()->unregister_gadget()->
> free udc_name->set udc_name to NULL
>
> Context 2:
> gadget_dev_desc_UDC_show()-> access udc_name
>
> Call trace:
> dump_backtrace+0x0/0x340
> show_stack+0x14/0x1c
> dump_stack+0xe4/0x134
> print_address_description+0x78/0x478
> __kasan_report+0x270/0x2ec
> kasan_report+0x10/0x18
> __asan_report_load1_noabort+0x18/0x20
> string+0xf4/0x138
> vsnprintf+0x428/0x14d0
> sprintf+0xe4/0x12c
> gadget_dev_desc_UDC_show+0x54/0x64
> configfs_read_file+0x210/0x3a0
> __vfs_read+0xf0/0x49c
> vfs_read+0x130/0x2b4
> SyS_read+0x114/0x208
> el0_svc_naked+0x34/0x38
>
> Add mutex_lock to protect this kind of scenario.
>
> Signed-off-by: Eddie Hung <eddie.hung@mediatek.com>
> Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
> Reviewed-by: Peter Chen <peter.chen@nxp.com>
> Cc: stable@vger.kernel.org
> Link: https://lore.kernel.org/r/1609239215-21819-1-git-send-email-macpaul.lin@mediatek.com
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> [Reference: CVE-2021-39648]
> [iwamatsu: struct usb_gadget_driver does not have udc_name variable.
> Change struct gadget_info's udc_name.]
> Signed-off-by: Nobuhiro Iwamatsu (CIP) <nobuhiro1.iwamatsu@toshiba.co.jp>
> ---
> drivers/usb/gadget/configfs.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
Now queued up, thanks.
greg k-h
next prev parent reply other threads:[~2021-12-27 12:47 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-23 5:26 [RFC/PATCH for 4.4.y] usb: gadget: configfs: Fix use-after-free issue with udc_name Nobuhiro Iwamatsu
2021-12-27 12:47 ` Greg KH [this message]
2021-12-27 13:10 ` Greg KH
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