cve/published/2024/CVE-2024-36009.mbox

From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: <linux-cve-announce@vger.kernel.org>
Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org>
Subject: CVE-2024-36009: ax25: Fix netdev refcount issue

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

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

ax25: Fix netdev refcount issue

The dev_tracker is added to ax25_cb in ax25_bind(). When the
ax25 device is detaching, the dev_tracker of ax25_cb should be
deallocated in ax25_kill_by_device() instead of the dev_tracker
of ax25_dev. The log reported by ref_tracker is shown below:

[   80.884935] ref_tracker: reference already released.
[   80.885150] ref_tracker: allocated in:
[   80.885349]  ax25_dev_device_up+0x105/0x540
[   80.885730]  ax25_device_event+0xa4/0x420
[   80.885730]  notifier_call_chain+0xc9/0x1e0
[   80.885730]  __dev_notify_flags+0x138/0x280
[   80.885730]  dev_change_flags+0xd7/0x180
[   80.885730]  dev_ifsioc+0x6a9/0xa30
[   80.885730]  dev_ioctl+0x4d8/0xd90
[   80.885730]  sock_do_ioctl+0x1c2/0x2d0
[   80.885730]  sock_ioctl+0x38b/0x4f0
[   80.885730]  __se_sys_ioctl+0xad/0xf0
[   80.885730]  do_syscall_64+0xc4/0x1b0
[   80.885730]  entry_SYSCALL_64_after_hwframe+0x67/0x6f
[   80.885730] ref_tracker: freed in:
[   80.885730]  ax25_device_event+0x272/0x420
[   80.885730]  notifier_call_chain+0xc9/0x1e0
[   80.885730]  dev_close_many+0x272/0x370
[   80.885730]  unregister_netdevice_many_notify+0x3b5/0x1180
[   80.885730]  unregister_netdev+0xcf/0x120
[   80.885730]  sixpack_close+0x11f/0x1b0
[   80.885730]  tty_ldisc_kill+0xcb/0x190
[   80.885730]  tty_ldisc_hangup+0x338/0x3d0
[   80.885730]  __tty_hangup+0x504/0x740
[   80.885730]  tty_release+0x46e/0xd80
[   80.885730]  __fput+0x37f/0x770
[   80.885730]  __x64_sys_close+0x7b/0xb0
[   80.885730]  do_syscall_64+0xc4/0x1b0
[   80.885730]  entry_SYSCALL_64_after_hwframe+0x67/0x6f
[   80.893739] ------------[ cut here ]------------
[   80.894030] WARNING: CPU: 2 PID: 140 at lib/ref_tracker.c:255 ref_tracker_free+0x47b/0x6b0
[   80.894297] Modules linked in:
[   80.894929] CPU: 2 PID: 140 Comm: ax25_conn_rel_6 Not tainted 6.9.0-rc4-g8cd26fd90c1a #11
[   80.895190] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qem4
[   80.895514] RIP: 0010:ref_tracker_free+0x47b/0x6b0
[   80.895808] Code: 83 c5 18 4c 89 eb 48 c1 eb 03 8a 04 13 84 c0 0f 85 df 01 00 00 41 83 7d 00 00 75 4b 4c 89 ff 9
[   80.896171] RSP: 0018:ffff888009edf8c0 EFLAGS: 00000286
[   80.896339] RAX: 1ffff1100141ac00 RBX: 1ffff1100149463b RCX: dffffc0000000000
[   80.896502] RDX: 0000000000000001 RSI: 0000000000000246 RDI: ffff88800a0d6518
[   80.896925] RBP: ffff888009edf9b0 R08: ffff88806d3288d3 R09: 1ffff1100da6511a
[   80.897212] R10: dffffc0000000000 R11: ffffed100da6511b R12: ffff88800a4a31d4
[   80.897859] R13: ffff88800a4a31d8 R14: dffffc0000000000 R15: ffff88800a0d6518
[   80.898279] FS:  00007fd88b7fe700(0000) GS:ffff88806d300000(0000) knlGS:0000000000000000
[   80.899436] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   80.900181] CR2: 00007fd88c001d48 CR3: 000000000993e000 CR4: 00000000000006f0
...
[   80.935774] ref_tracker: sp%d@000000000bb9df3d has 1/1 users at
[   80.935774]      ax25_bind+0x424/0x4e0
[   80.935774]      __sys_bind+0x1d9/0x270
[   80.935774]      __x64_sys_bind+0x75/0x80
[   80.935774]      do_syscall_64+0xc4/0x1b0
[   80.935774]      entry_SYSCALL_64_after_hwframe+0x67/0x6f

Change ax25_dev->dev_tracker to the dev_tracker of ax25_cb
in order to mitigate the bug.

The Linux kernel CVE team has assigned CVE-2024-36009 to this issue.


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

	Issue introduced in 5.17 with commit feef318c855a361a1eccd880f33e88c460eb63b4 and fixed in 6.1.90 with commit 0d14f104027e30720582448706c7d6b43065c851
	Issue introduced in 5.17 with commit feef318c855a361a1eccd880f33e88c460eb63b4 and fixed in 6.6.30 with commit 4fee8fa86a15d7790268eea458b1aec69c695530
	Issue introduced in 5.17 with commit feef318c855a361a1eccd880f33e88c460eb63b4 and fixed in 6.8.9 with commit c42b073d9af4a5329b25b17390c63ab3847f30e8
	Issue introduced in 5.17 with commit feef318c855a361a1eccd880f33e88c460eb63b4 and fixed in 6.9 with commit 467324bcfe1a31ec65d0cf4aa59421d6b7a7d52b
	Issue introduced in 4.14.277 with commit b8c07f33aa35dacf5444e7053ed9662d1869f536
	Issue introduced in 4.19.240 with commit b1e0a6fc7f17500484c402ad1cd018c24dfc14b3
	Issue introduced in 5.4.190 with commit 7528d0f2210c3a1154186175516ed37aa970f2b1
	Issue introduced in 5.10.112 with commit 57cc15f5fd550316e4104eaf84b90fbc640fd7a5
	Issue introduced in 5.15.35 with commit b982492ec3a115e0a136856a1b2dbe32f2d21a0e

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-2024-36009
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/ax25/af_ax25.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/0d14f104027e30720582448706c7d6b43065c851
	https://git.kernel.org/stable/c/4fee8fa86a15d7790268eea458b1aec69c695530
	https://git.kernel.org/stable/c/c42b073d9af4a5329b25b17390c63ab3847f30e8
	https://git.kernel.org/stable/c/467324bcfe1a31ec65d0cf4aa59421d6b7a7d52b