// For flags

CVE-2021-47393

hwmon: (mlxreg-fan) Return non-zero value when fan current state is enforced from sysfs

Severity Score

4.7
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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

hwmon: (mlxreg-fan) Return non-zero value when fan current state is enforced from sysfs

Fan speed minimum can be enforced from sysfs. For example, setting
current fan speed to 20 is used to enforce fan speed to be at 100%
speed, 19 - to be not below 90% speed, etcetera. This feature provides
ability to limit fan speed according to some system wise
considerations, like absence of some replaceable units or high system
ambient temperature.

Request for changing fan minimum speed is configuration request and can
be set only through 'sysfs' write procedure. In this situation value of
argument 'state' is above nominal fan speed maximum.

Return non-zero code in this case to avoid
thermal_cooling_device_stats_update() call, because in this case
statistics update violates thermal statistics table range.
The issues is observed in case kernel is configured with option
CONFIG_THERMAL_STATISTICS.

Here is the trace from KASAN:
[ 159.506659] BUG: KASAN: slab-out-of-bounds in thermal_cooling_device_stats_update+0x7d/0xb0
[ 159.516016] Read of size 4 at addr ffff888116163840 by task hw-management.s/7444
[ 159.545625] Call Trace:
[ 159.548366] dump_stack+0x92/0xc1
[ 159.552084] ? thermal_cooling_device_stats_update+0x7d/0xb0
[ 159.635869] thermal_zone_device_update+0x345/0x780
[ 159.688711] thermal_zone_device_set_mode+0x7d/0xc0
[ 159.694174] mlxsw_thermal_modules_init+0x48f/0x590 [mlxsw_core]
[ 159.700972] ? mlxsw_thermal_set_cur_state+0x5a0/0x5a0 [mlxsw_core]
[ 159.731827] mlxsw_thermal_init+0x763/0x880 [mlxsw_core]
[ 160.070233] RIP: 0033:0x7fd995909970
[ 160.074239] Code: 73 01 c3 48 8b 0d 28 d5 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 99 2d 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ..
[ 160.095242] RSP: 002b:00007fff54f5d938 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 160.103722] RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 00007fd995909970
[ 160.111710] RDX: 0000000000000013 RSI: 0000000001906008 RDI: 0000000000000001
[ 160.119699] RBP: 0000000001906008 R08: 00007fd995bc9760 R09: 00007fd996210700
[ 160.127687] R10: 0000000000000073 R11: 0000000000000246 R12: 0000000000000013
[ 160.135673] R13: 0000000000000001 R14: 00007fd995bc8600 R15: 0000000000000013
[ 160.143671]
[ 160.145338] Allocated by task 2924:
[ 160.149242] kasan_save_stack+0x19/0x40
[ 160.153541] __kasan_kmalloc+0x7f/0xa0
[ 160.157743] __kmalloc+0x1a2/0x2b0
[ 160.161552] thermal_cooling_device_setup_sysfs+0xf9/0x1a0
[ 160.167687] __thermal_cooling_device_register+0x1b5/0x500
[ 160.173833] devm_thermal_of_cooling_device_register+0x60/0xa0
[ 160.180356] mlxreg_fan_probe+0x474/0x5e0 [mlxreg_fan]
[ 160.248140]
[ 160.249807] The buggy address belongs to the object at ffff888116163400
[ 160.249807] which belongs to the cache kmalloc-1k of size 1024
[ 160.263814] The buggy address is located 64 bytes to the right of
[ 160.263814] 1024-byte region [ffff888116163400, ffff888116163800)
[ 160.277536] The buggy address belongs to the page:
[ 160.282898] page:0000000012275840 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888116167000 pfn:0x116160
[ 160.294872] head:0000000012275840 order:3 compound_mapcount:0 compound_pincount:0
[ 160.303251] flags: 0x200000000010200(slab|head|node=0|zone=2)
[ 160.309694] raw: 0200000000010200 ffffea00046f7208 ffffea0004928208 ffff88810004dbc0
[ 160.318367] raw: ffff888116167000 00000000000a0006 00000001ffffffff 0000000000000000
[ 160.327033] page dumped because: kasan: bad access detected
[ 160.333270]
[ 160.334937] Memory state around the buggy address:
[ 160.356469] >ffff888116163800: fc ..

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: hwmon: (mlxreg-fan) Devuelve un valor distinto de cero cuando el estado actual del ventilador se aplica desde sysfs. La velocidad mínima del ventilador se puede aplicar desde sysfs. Por ejemplo, configurar la velocidad actual del ventilador en 20 se utiliza para hacer que la velocidad del ventilador esté al 100 %, 19, para que no esté por debajo del 90 %, etcétera. Esta característica brinda la capacidad de limitar la velocidad del ventilador de acuerdo con algunas consideraciones del sistema, como la ausencia de algunas unidades reemplazables o la alta temperatura ambiente del sistema. La solicitud para cambiar la velocidad mínima del ventilador es una solicitud de configuración y solo se puede configurar mediante el procedimiento de escritura 'sysfs'. En esta situación, el valor del argumento "estado" está por encima de la velocidad máxima nominal del ventilador. En este caso, devuelva un código distinto de cero para evitar la llamada a Thermal_cooling_device_stats_update(), porque en este caso la actualización de estadísticas viola el rango de la tabla de estadísticas térmicas. Los problemas se observan en caso de que el kernel esté configurado con la opción CONFIG_THERMAL_STATISTICS. Aquí está el rastro de KASAN: [159.506659] ERROR: KASAN: slab fuera de los límites en Thermal_cooling_device_stats_update+0x7d/0xb0 [159.516016] Lectura de tamaño 4 en la dirección ffff888116163840 mediante la tarea hw-management.s/7444 [ 625] Llamada Seguimiento: [159.548366] dump_stack+0x92/0xc1 [159.552084]? Thermal_cooling_device_stats_update+0x7d/0xb0 [ 159.635869] Thermal_zone_device_update+0x345/0x780 [ 159.688711] Thermal_zone_device_set_mode+0x7d/0xc0 [ 159.694174] mlxsw_thermal_modules_init+0x48f /0x590 [mlxsw_core] [159.700972]? mlxsw_thermal_set_cur_state+0x5a0/0x5a0 [mlxsw_core] [ 159.731827] mlxsw_thermal_init+0x763/0x880 [mlxsw_core] [ 160.070233] RIP: 0033:0x7fd995909970 [ 160.07423 9] Código: 73 01 c3 48 8b 0d 28 d5 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 99 2d 2c 00 00 75 10 b8 01 00 00 00 0f 05 &lt;48&gt; 3d 01 f0 ff .. [ 160.095242] RSP: 00007fff54f5d938 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 160.103722] RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 00007fd995909970 [ 160.111710] RDX: 00000000000000013 RSI: 0000000001906008 RDI: 000000000000 0001 [ 160.119699] RBP: 0000000001906008 R08: 00007fd995bc9760 R09: 00007fd996210700 [ 160.127687] R10: 0000000000000073 R11: 000000246 R12: 00000000000000013 [ 160.135673] R13: 0000000000000001 R14: 00007fd995bc8600 R15: 0000000000000013 [ 160.143671] [ 160.145338] Asignado por tarea 2924: [ 160.149242] x40 [ 160.153541] __kasan_kmalloc+0x7f/0xa0 [ 160.157743] __kmalloc+0x1a2/0x2b0 [ 160.161552] Thermal_cooling_device_setup_sysfs+0xf9/0x1a0 [ 160.167687] __thermal_cooling_device_register+0x1b5/0x500 [ 160.173833] devm_thermal_of_cooling_device_register+0x60/0xa0 [ 160.180356] mlxreg_fan_probe+0x474/0x5e0 [mlxreg_fan] [ 160. 248140] [160.249807] La dirección con errores pertenece al objeto en ffff888116163400 [160.249807] que pertenece al caché kmalloc-1k de tamaño 1024 [ 160.263814] La dirección con errores se encuentra 64 bytes a la derecha de [ 160.263814] Región de 1024 bytes [ffff888116163400, ffff888116163800) [ 160.277536] La dirección con errores pertenece a la página: [ 160.2 82898] página:0000000012275840 refcount :1 mapcount:0 mapeo:0000000000000000 índice:0xffff888116167000 pfn:0x116160 [ 160.294872] head:0000000012275840 orden:3 compuesto_mapcount:0 compuesto_pincount:0 [ 160.303251] banderas: 00000010200(slab|cabeza|nodo=0|zona=2) [ 160.309694 ] sin formato: 0200000000010200 ffffea00046f7208 ffffea0004928208 ffff88810004dbc0 [ 160.318367] sin formato: ffff888116167000 00000000000a0006 00000001ffffffff 0000000000000000 [160.327033] página volcada porque: kasan: mal acceso detectado [160.333270] [160.334937] Estado de la memoria alrededor de la dirección con errores: [160.356469] &gt;ffff888116163800: fc ..

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-05-21 CVE Reserved
  • 2024-05-21 CVE Published
  • 2024-05-22 EPSS Updated
  • 2024-12-19 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-754: Improper Check for Unusual or Exceptional Conditions
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.19 < 4.19.209
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.19 < 4.19.209"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.19 < 5.4.151
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.19 < 5.4.151"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.19 < 5.10.71
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.19 < 5.10.71"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.19 < 5.14.10
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.19 < 5.14.10"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.19 < 5.15
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.19 < 5.15"
en
Affected