From: Yang Yingliang <yangyingliang@huawei.com>
To: <netdev@vger.kernel.org>
Cc: <jiri@nvidia.com>, <davem@davemloft.net>, <edumazet@google.com>,
<kuba@kernel.org>, <pabeni@redhat.com>
Subject: [PATCH net] net: devlink: fix UAF in devlink_compat_running_version()
Date: Tue, 22 Nov 2022 20:10:48 +0800 [thread overview]
Message-ID: <20221122121048.776643-1-yangyingliang@huawei.com> (raw)
I got a UAF report as following when doing fault injection test:
BUG: KASAN: use-after-free in devlink_compat_running_version+0x5b9/0x6a0
Read of size 8 at addr ffff88810ac591f0 by task systemd-udevd/458
CPU: 2 PID: 458 Comm: systemd-udevd Not tainted 6.1.0-rc5-00155-ga9d2b54dd4e7-dirty #1359
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
<TASK>
kasan_report+0x90/0x190
devlink_compat_running_version+0x5b9/0x6a0
dev_ethtool+0x2ca/0x340
dev_ioctl+0x16c/0xff0
sock_do_ioctl+0x1ae/0x220
Allocated by task 456:
kasan_save_stack+0x1c/0x40
kasan_set_track+0x21/0x30
__kasan_kmalloc+0x7e/0x90
__kmalloc+0x59/0x1b0
devlink_alloc_ns+0xf7/0xa10
nsim_drv_probe+0xa8/0x150 [netdevsim]
really_probe+0x1ff/0x660
Freed by task 456:
kasan_save_stack+0x1c/0x40
kasan_set_track+0x21/0x30
kasan_save_free_info+0x2a/0x50
__kasan_slab_free+0x102/0x190
__kmem_cache_free+0xca/0x400
nsim_drv_probe.cold.31+0x2af/0xf62 [netdevsim]
really_probe+0x1ff/0x660
It happened like this:
processor A processor B
nsim_drv_probe()
devlink_alloc_ns()
nsim_dev_port_add_all()
__nsim_dev_port_add() // add eth1 successful
dev_ethtool()
ethtool_get_drvinfo(eth1)
netdev_to_devlink_get(eth1)
devlink_try_get() // get devlink here
__nsim_dev_port_add() // add eth2 failed, goto error
devlink_free() // it's called in the error path
devlink_compat_running_version() <- causes UAF
devlink_register() // it's in normal path, not called yet
There is two ports to add in nsim_dev_port_add_all(), if first
port is added successful, the devlink is visable and can be get
by devlink_try_get() on another cpu, but it is not registered
yet. And then the second port is failed to added, in the error
path, devlink_free() is called, at last it causes UAF.
Add check in devlink_try_get(), if the 'devlink' is not registered
it returns NULL to avoid UAF like this case.
Fixes: a62fdbbe9403 ("netdevsim: implement ndo_get_devlink_port")
Reported-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
net/core/devlink.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 89baa7c0938b..6453ac0558fb 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -250,6 +250,9 @@ void devlink_put(struct devlink *devlink)
struct devlink *__must_check devlink_try_get(struct devlink *devlink)
{
+ if (!xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED))
+ return NULL;
+
if (refcount_inc_not_zero(&devlink->refcount))
return devlink;
return NULL;
--
2.25.1
next reply other threads:[~2022-11-22 12:12 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-22 12:10 Yang Yingliang [this message]
2022-11-22 14:32 ` [PATCH net] net: devlink: fix UAF in devlink_compat_running_version() Leon Romanovsky
2022-11-22 15:25 ` Yang Yingliang
2022-11-22 19:04 ` Leon Romanovsky
2022-11-22 20:27 ` Jakub Kicinski
2022-11-23 1:50 ` Yang Yingliang
2022-11-23 6:40 ` Yang Yingliang
2022-11-23 7:41 ` Leon Romanovsky
2022-11-23 8:34 ` Yang Yingliang
2022-11-23 9:33 ` Leon Romanovsky
2022-11-23 19:18 ` Ido Schimmel
2022-11-24 2:18 ` Jakub Kicinski
2022-11-24 5:56 ` Leon Romanovsky
2022-11-28 9:20 ` Ido Schimmel
2022-11-28 9:58 ` Jiri Pirko
2022-11-28 11:50 ` Leon Romanovsky
2022-11-28 13:52 ` Jiri Pirko
2022-11-29 8:44 ` Leon Romanovsky
2022-11-29 9:05 ` Jiri Pirko
2022-11-29 11:20 ` Leon Romanovsky
2022-11-29 11:44 ` Jiri Pirko
2022-11-28 18:20 ` Jakub Kicinski
2022-11-29 8:31 ` Jiri Pirko
2022-11-30 2:18 ` Jakub Kicinski
2022-11-30 8:54 ` Leon Romanovsky
2022-11-30 11:32 ` Jiri Pirko
2022-11-30 16:36 ` Jakub Kicinski
2022-11-30 11:42 ` Jiri Pirko
2022-11-30 16:46 ` Jakub Kicinski
2022-11-30 17:00 ` Jiri Pirko
2022-11-30 17:20 ` Jakub Kicinski
2022-11-30 19:20 ` Leon Romanovsky
2022-12-01 8:40 ` Jiri Pirko
2022-12-01 10:05 ` Leon Romanovsky
2022-12-01 12:20 ` Jiri Pirko
2022-12-01 8:39 ` Jiri Pirko
2022-11-30 22:25 ` Jacob Keller
2022-11-24 2:20 ` Jakub Kicinski
2022-11-24 2:47 ` Jakub Kicinski
2022-11-24 7:28 ` Yang Yingliang
2022-11-28 10:01 ` Jiri Pirko
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