cve/published/2023/CVE-2023-53138.mbox

From bippy-1.1.0 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@kernel.org>
To: <linux-cve-announce@vger.kernel.org>
Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org>
Subject: CVE-2023-53138: net: caif: Fix use-after-free in cfusbl_device_notify()

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

net: caif: Fix use-after-free in cfusbl_device_notify()

syzbot reported use-after-free in cfusbl_device_notify() [1].  This
causes a stack trace like below:

BUG: KASAN: use-after-free in cfusbl_device_notify+0x7c9/0x870 net/caif/caif_usb.c:138
Read of size 8 at addr ffff88807ac4e6f0 by task kworker/u4:6/1214

CPU: 0 PID: 1214 Comm: kworker/u4:6 Not tainted 5.19.0-rc3-syzkaller-00146-g92f20ff72066 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0xeb/0x467 mm/kasan/report.c:313
 print_report mm/kasan/report.c:429 [inline]
 kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491
 cfusbl_device_notify+0x7c9/0x870 net/caif/caif_usb.c:138
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1945
 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline]
 call_netdevice_notifiers net/core/dev.c:1997 [inline]
 netdev_wait_allrefs_any net/core/dev.c:10227 [inline]
 netdev_run_todo+0xbc0/0x10f0 net/core/dev.c:10341
 default_device_exit_batch+0x44e/0x590 net/core/dev.c:11334
 ops_exit_list+0x125/0x170 net/core/net_namespace.c:167
 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594
 process_one_work+0x996/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
 </TASK>

When unregistering a net device, unregister_netdevice_many_notify()
sets the device's reg_state to NETREG_UNREGISTERING, calls notifiers
with NETDEV_UNREGISTER, and adds the device to the todo list.

Later on, devices in the todo list are processed by netdev_run_todo().
netdev_run_todo() waits devices' reference count become 1 while
rebdoadcasting NETDEV_UNREGISTER notification.

When cfusbl_device_notify() is called with NETDEV_UNREGISTER multiple
times, the parent device might be freed.  This could cause UAF.
Processing NETDEV_UNREGISTER multiple times also causes inbalance of
reference count for the module.

This patch fixes the issue by accepting only first NETDEV_UNREGISTER
notification.

The Linux kernel CVE team has assigned CVE-2023-53138 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 3.3 with commit 7ad65bf68d705b445ef10b77ab50dab22be185ee and fixed in 4.14.310 with commit 68a45c3cf0e2242a533657f4f535d9b6a7447a79
	Issue introduced in 3.3 with commit 7ad65bf68d705b445ef10b77ab50dab22be185ee and fixed in 4.19.278 with commit 1793da97a23e31c5bf06631f3f3e5a25f368fd64
	Issue introduced in 3.3 with commit 7ad65bf68d705b445ef10b77ab50dab22be185ee and fixed in 5.4.237 with commit 9dc16be373b382ddd4c274052a6e870a95e76c01
	Issue introduced in 3.3 with commit 7ad65bf68d705b445ef10b77ab50dab22be185ee and fixed in 5.10.175 with commit c3aaec463a632cf4187dc017e421bfa69d7834a9
	Issue introduced in 3.3 with commit 7ad65bf68d705b445ef10b77ab50dab22be185ee and fixed in 5.15.103 with commit 3f14457e1584224f4296af613bbd99deb60b5d91
	Issue introduced in 3.3 with commit 7ad65bf68d705b445ef10b77ab50dab22be185ee and fixed in 6.1.20 with commit 287027d8a567168a5d8ce5cb0cba16a34791a48c
	Issue introduced in 3.3 with commit 7ad65bf68d705b445ef10b77ab50dab22be185ee and fixed in 6.2.7 with commit d1a11bbdbb5ea9f172019c5a4a3e9d8eabd72179
	Issue introduced in 3.3 with commit 7ad65bf68d705b445ef10b77ab50dab22be185ee and fixed in 6.3 with commit 9781e98a97110f5e76999058368b4be76a788484

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2023-53138
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	net/caif/caif_usb.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/68a45c3cf0e2242a533657f4f535d9b6a7447a79
	https://git.kernel.org/stable/c/1793da97a23e31c5bf06631f3f3e5a25f368fd64
	https://git.kernel.org/stable/c/9dc16be373b382ddd4c274052a6e870a95e76c01
	https://git.kernel.org/stable/c/c3aaec463a632cf4187dc017e421bfa69d7834a9
	https://git.kernel.org/stable/c/3f14457e1584224f4296af613bbd99deb60b5d91
	https://git.kernel.org/stable/c/287027d8a567168a5d8ce5cb0cba16a34791a48c
	https://git.kernel.org/stable/c/d1a11bbdbb5ea9f172019c5a4a3e9d8eabd72179
	https://git.kernel.org/stable/c/9781e98a97110f5e76999058368b4be76a788484