From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Schspa Shi <schspa@gmail.com>,
syzbot+dc7c3ca638e773db07f6@syzkaller.appspotmail.com,
Andrey Konovalov <andreyknvl@gmail.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sasha Levin <sashal@kernel.org>,
balbi@kernel.org, jj251510319013@gmail.com,
Julia.Lawall@inria.fr, jannh@google.com,
linux-usb@vger.kernel.org
Subject: [PATCH AUTOSEL 5.10 13/13] usb: gadget: fix race when gadget driver register via ioctl
Date: Wed, 18 May 2022 08:28:44 -0400 [thread overview]
Message-ID: <20220518122844.343220-13-sashal@kernel.org> (raw)
In-Reply-To: <20220518122844.343220-1-sashal@kernel.org>
From: Schspa Shi <schspa@gmail.com>
[ Upstream commit 5f0b5f4d50fa0faa8c76ef9d42a42e8d43f98b44 ]
The usb_gadget_register_driver can be called multi time by to
threads via USB_RAW_IOCTL_RUN ioctl syscall, which will lead
to multiple registrations.
Call trace:
driver_register+0x220/0x3a0 drivers/base/driver.c:171
usb_gadget_register_driver_owner+0xfb/0x1e0
drivers/usb/gadget/udc/core.c:1546
raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:513 [inline]
raw_ioctl+0x1883/0x2730 drivers/usb/gadget/legacy/raw_gadget.c:1220
ioctl USB_RAW_IOCTL_RUN
This routine allows two processes to register the same driver instance
via ioctl syscall. which lead to a race condition.
Please refer to the following scenarios.
T1 T2
------------------------------------------------------------------
usb_gadget_register_driver_owner
driver_register driver_register
driver_find driver_find
bus_add_driver bus_add_driver
priv alloced <context switch>
drv->p = priv;
<schedule out>
kobject_init_and_add // refcount = 1;
//couldn't find an available UDC or it's busy
<context switch>
priv alloced
drv->priv = priv;
kobject_init_and_add
---> refcount = 1 <------
// register success
<context switch>
===================== another ioctl/process ======================
driver_register
driver_find
k = kset_find_obj()
---> refcount = 2 <------
<context out>
driver_unregister
// drv->p become T2's priv
---> refcount = 1 <------
<context switch>
kobject_put(k)
---> refcount = 0 <------
return priv->driver;
--------UAF here----------
There will be UAF in this scenario.
We can fix it by adding a new STATE_DEV_REGISTERING device state to
avoid double register.
Reported-by: syzbot+dc7c3ca638e773db07f6@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/000000000000e66c2805de55b15a@google.com/
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Schspa Shi <schspa@gmail.com>
Link: https://lore.kernel.org/r/20220508150247.38204-1-schspa@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/gadget/legacy/raw_gadget.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/usb/gadget/legacy/raw_gadget.c b/drivers/usb/gadget/legacy/raw_gadget.c
index 33efa6915b91..34cecd3660bf 100644
--- a/drivers/usb/gadget/legacy/raw_gadget.c
+++ b/drivers/usb/gadget/legacy/raw_gadget.c
@@ -144,6 +144,7 @@ enum dev_state {
STATE_DEV_INVALID = 0,
STATE_DEV_OPENED,
STATE_DEV_INITIALIZED,
+ STATE_DEV_REGISTERING,
STATE_DEV_RUNNING,
STATE_DEV_CLOSED,
STATE_DEV_FAILED
@@ -507,6 +508,7 @@ static int raw_ioctl_run(struct raw_dev *dev, unsigned long value)
ret = -EINVAL;
goto out_unlock;
}
+ dev->state = STATE_DEV_REGISTERING;
spin_unlock_irqrestore(&dev->lock, flags);
ret = usb_gadget_probe_driver(&dev->driver);
--
2.35.1
prev parent reply other threads:[~2022-05-18 12:34 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-18 12:28 [PATCH AUTOSEL 5.10 01/13] scsi: qla2xxx: Fix missed DMA unmap for aborted commands Sasha Levin
2022-05-18 12:28 ` [PATCH AUTOSEL 5.10 02/13] mac80211: fix rx reordering with non explicit / psmp ack policy Sasha Levin
2022-05-18 12:28 ` [PATCH AUTOSEL 5.10 03/13] nl80211: validate S1G channel width Sasha Levin
2022-05-18 12:28 ` [PATCH AUTOSEL 5.10 04/13] selftests: add ping test with ping_group_range tuned Sasha Levin
2022-05-18 12:28 ` [PATCH AUTOSEL 5.10 05/13] nl80211: fix locking in nl80211_set_tx_bitrate_mask() Sasha Levin
2022-05-18 12:28 ` [PATCH AUTOSEL 5.10 06/13] ethernet: tulip: fix missing pci_disable_device() on error in tulip_init_one() Sasha Levin
2022-05-18 12:28 ` [PATCH AUTOSEL 5.10 07/13] net: stmmac: fix missing pci_disable_device() on error in stmmac_pci_probe() Sasha Levin
2022-05-18 12:28 ` [PATCH AUTOSEL 5.10 08/13] net: atlantic: fix "frag[0] not initialized" Sasha Levin
2022-05-18 12:28 ` [PATCH AUTOSEL 5.10 09/13] net: atlantic: reduce scope of is_rsc_complete Sasha Levin
2022-05-18 12:28 ` [PATCH AUTOSEL 5.10 10/13] net: atlantic: add check for MAX_SKB_FRAGS Sasha Levin
2022-05-18 12:28 ` [PATCH AUTOSEL 5.10 11/13] net: atlantic: verify hw_head_ lies within TX buffer ring Sasha Levin
2022-05-18 12:28 ` [PATCH AUTOSEL 5.10 12/13] arm64: Enable repeat tlbi workaround on KRYO4XX gold CPUs Sasha Levin
2022-05-18 12:28 ` Sasha Levin [this message]
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