cve/published/2024/CVE-2024-56587.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-2024-56587: leds: class: Protect brightness_show() with led_cdev->led_access mutex

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

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

leds: class: Protect brightness_show() with led_cdev->led_access mutex

There is NULL pointer issue observed if from Process A where hid device
being added which results in adding a led_cdev addition and later a
another call to access of led_cdev attribute from Process B can result
in NULL pointer issue.

Use mutex led_cdev->led_access to protect access to led->cdev and its
attribute inside brightness_show() and max_brightness_show() and also
update the comment for mutex that it should be used to protect the led
class device fields.

	Process A 				Process B

 kthread+0x114
 worker_thread+0x244
 process_scheduled_works+0x248
 uhid_device_add_worker+0x24
 hid_add_device+0x120
 device_add+0x268
 bus_probe_device+0x94
 device_initial_probe+0x14
 __device_attach+0xfc
 bus_for_each_drv+0x10c
 __device_attach_driver+0x14c
 driver_probe_device+0x3c
 __driver_probe_device+0xa0
 really_probe+0x190
 hid_device_probe+0x130
 ps_probe+0x990
 ps_led_register+0x94
 devm_led_classdev_register_ext+0x58
 led_classdev_register_ext+0x1f8
 device_create_with_groups+0x48
 device_create_groups_vargs+0xc8
 device_add+0x244
 kobject_uevent+0x14
 kobject_uevent_env[jt]+0x224
 mutex_unlock[jt]+0xc4
 __mutex_unlock_slowpath+0xd4
 wake_up_q+0x70
 try_to_wake_up[jt]+0x48c
 preempt_schedule_common+0x28
 __schedule+0x628
 __switch_to+0x174
						el0t_64_sync+0x1a8/0x1ac
						el0t_64_sync_handler+0x68/0xbc
						el0_svc+0x38/0x68
						do_el0_svc+0x1c/0x28
						el0_svc_common+0x80/0xe0
						invoke_syscall+0x58/0x114
						__arm64_sys_read+0x1c/0x2c
						ksys_read+0x78/0xe8
						vfs_read+0x1e0/0x2c8
						kernfs_fop_read_iter+0x68/0x1b4
						seq_read_iter+0x158/0x4ec
						kernfs_seq_show+0x44/0x54
						sysfs_kf_seq_show+0xb4/0x130
						dev_attr_show+0x38/0x74
						brightness_show+0x20/0x4c
						dualshock4_led_get_brightness+0xc/0x74

[ 3313.874295][ T4013] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000060
[ 3313.874301][ T4013] Mem abort info:
[ 3313.874303][ T4013]   ESR = 0x0000000096000006
[ 3313.874305][ T4013]   EC = 0x25: DABT (current EL), IL = 32 bits
[ 3313.874307][ T4013]   SET = 0, FnV = 0
[ 3313.874309][ T4013]   EA = 0, S1PTW = 0
[ 3313.874311][ T4013]   FSC = 0x06: level 2 translation fault
[ 3313.874313][ T4013] Data abort info:
[ 3313.874314][ T4013]   ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000
[ 3313.874316][ T4013]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 3313.874318][ T4013]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 3313.874320][ T4013] user pgtable: 4k pages, 39-bit VAs, pgdp=00000008f2b0a000
..

[ 3313.874332][ T4013] Dumping ftrace buffer:
[ 3313.874334][ T4013]    (ftrace buffer empty)
..
..
[ dd3313.874639][ T4013] CPU: 6 PID: 4013 Comm: InputReader
[ 3313.874648][ T4013] pc : dualshock4_led_get_brightness+0xc/0x74
[ 3313.874653][ T4013] lr : led_update_brightness+0x38/0x60
[ 3313.874656][ T4013] sp : ffffffc0b910bbd0
..
..
[ 3313.874685][ T4013] Call trace:
[ 3313.874687][ T4013]  dualshock4_led_get_brightness+0xc/0x74
[ 3313.874690][ T4013]  brightness_show+0x20/0x4c
[ 3313.874692][ T4013]  dev_attr_show+0x38/0x74
[ 3313.874696][ T4013]  sysfs_kf_seq_show+0xb4/0x130
[ 3313.874700][ T4013]  kernfs_seq_show+0x44/0x54
[ 3313.874703][ T4013]  seq_read_iter+0x158/0x4ec
[ 3313.874705][ T4013]  kernfs_fop_read_iter+0x68/0x1b4
[ 3313.874708][ T4013]  vfs_read+0x1e0/0x2c8
[ 3313.874711][ T4013]  ksys_read+0x78/0xe8
[ 3313.874714][ T4013]  __arm64_sys_read+0x1c/0x2c
[ 3313.874718][ T4013]  invoke_syscall+0x58/0x114
[ 3313.874721][ T4013]  el0_svc_common+0x80/0xe0
[ 3313.874724][ T4013]  do_el0_svc+0x1c/0x28
[ 3313.874727][ T4013]  el0_svc+0x38/0x68
[ 3313.874730][ T4013]  el0t_64_sync_handler+0x68/0xbc
[ 3313.874732][ T4013]  el0t_64_sync+0x1a8/0x1ac

The Linux kernel CVE team has assigned CVE-2024-56587 to this issue.


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

	Fixed in 5.4.287 with commit 84b42d5b5fcd767c9b7f30b0b32065ed949fe804
	Fixed in 5.10.231 with commit ddcfc5708da9972ac23a9121b3d819b0a53d6f21
	Fixed in 5.15.174 with commit b8283d52ed15c02bb2eb9b1b8644dcc34f8e98f1
	Fixed in 6.1.120 with commit 50d9f68e4adf86901cbab1bd5b91f710aa9141b9
	Fixed in 6.6.66 with commit f6d6fb563e4be245a17bc4261a4b294e8bf8a31e
	Fixed in 6.12.5 with commit bb4a6236a430cfc3713f470f3a969f39d6d4ca25
	Fixed in 6.13 with commit 4ca7cd938725a4050dcd62ae9472e931d603118d

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-2024-56587
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:
	drivers/leds/led-class.c
	include/linux/leds.h


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/84b42d5b5fcd767c9b7f30b0b32065ed949fe804
	https://git.kernel.org/stable/c/ddcfc5708da9972ac23a9121b3d819b0a53d6f21
	https://git.kernel.org/stable/c/b8283d52ed15c02bb2eb9b1b8644dcc34f8e98f1
	https://git.kernel.org/stable/c/50d9f68e4adf86901cbab1bd5b91f710aa9141b9
	https://git.kernel.org/stable/c/f6d6fb563e4be245a17bc4261a4b294e8bf8a31e
	https://git.kernel.org/stable/c/bb4a6236a430cfc3713f470f3a969f39d6d4ca25
	https://git.kernel.org/stable/c/4ca7cd938725a4050dcd62ae9472e931d603118d