// For flags

CVE-2023-52635

PM / devfreq: Synchronize devfreq_monitor_[start/stop]

Severity Score

4.4
*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:

PM / devfreq: Synchronize devfreq_monitor_[start/stop]

There is a chance if a frequent switch of the governor
done in a loop result in timer list corruption where
timer cancel being done from two place one from
cancel_delayed_work_sync() and followed by expire_timers()
can be seen from the traces[1].

while true
do
echo "simple_ondemand" > /sys/class/devfreq/1d84000.ufshc/governor
echo "performance" > /sys/class/devfreq/1d84000.ufshc/governor
done

It looks to be issue with devfreq driver where
device_monitor_[start/stop] need to synchronized so that
delayed work should get corrupted while it is either
being queued or running or being cancelled.

Let's use polling flag and devfreq lock to synchronize the
queueing the timer instance twice and work data being
corrupted.

[1]
...
..
<idle>-0 [003] 9436.209662: timer_cancel timer=0xffffff80444f0428
<idle>-0 [003] 9436.209664: timer_expire_entry timer=0xffffff80444f0428 now=0x10022da1c function=__typeid__ZTSFvP10timer_listE_global_addr baseclk=0x10022da1c
<idle>-0 [003] 9436.209718: timer_expire_exit timer=0xffffff80444f0428
kworker/u16:6-14217 [003] 9436.209863: timer_start timer=0xffffff80444f0428 function=__typeid__ZTSFvP10timer_listE_global_addr expires=0x10022da2b now=0x10022da1c flags=182452227
vendor.xxxyyy.ha-1593 [004] 9436.209888: timer_cancel timer=0xffffff80444f0428
vendor.xxxyyy.ha-1593 [004] 9436.216390: timer_init timer=0xffffff80444f0428
vendor.xxxyyy.ha-1593 [004] 9436.216392: timer_start timer=0xffffff80444f0428 function=__typeid__ZTSFvP10timer_listE_global_addr expires=0x10022da2c now=0x10022da1d flags=186646532
vendor.xxxyyy.ha-1593 [005] 9436.220992: timer_cancel timer=0xffffff80444f0428
xxxyyyTraceManag-7795 [004] 9436.261641: timer_cancel timer=0xffffff80444f0428

[2]

9436.261653][ C4] Unable to handle kernel paging request at virtual address dead00000000012a
[ 9436.261664][ C4] Mem abort info:
[ 9436.261666][ C4] ESR = 0x96000044
[ 9436.261669][ C4] EC = 0x25: DABT (current EL), IL = 32 bits
[ 9436.261671][ C4] SET = 0, FnV = 0
[ 9436.261673][ C4] EA = 0, S1PTW = 0
[ 9436.261675][ C4] Data abort info:
[ 9436.261677][ C4] ISV = 0, ISS = 0x00000044
[ 9436.261680][ C4] CM = 0, WnR = 1
[ 9436.261682][ C4] [dead00000000012a] address between user and kernel address ranges
[ 9436.261685][ C4] Internal error: Oops: 96000044 [#1] PREEMPT SMP
[ 9436.261701][ C4] Skip md ftrace buffer dump for: 0x3a982d0
...

[ 9436.262138][ C4] CPU: 4 PID: 7795 Comm: TraceManag Tainted: G S W O 5.10.149-android12-9-o-g17f915d29d0c #1
[ 9436.262141][ C4] Hardware name: Qualcomm Technologies, Inc. (DT)
[ 9436.262144][ C4] pstate: 22400085 (nzCv daIf +PAN -UAO +TCO BTYPE=--)
[ 9436.262161][ C4] pc : expire_timers+0x9c/0x438
[ 9436.262164][ C4] lr : expire_timers+0x2a4/0x438
[ 9436.262168][ C4] sp : ffffffc010023dd0
[ 9436.262171][ C4] x29: ffffffc010023df0 x28: ffffffd0636fdc18
[ 9436.262178][ C4] x27: ffffffd063569dd0 x26: ffffffd063536008
[ 9436.262182][ C4] x25: 0000000000000001 x24: ffffff88f7c69280
[ 9436.262185][ C4] x23: 00000000000000e0 x22: dead000000000122
[ 9436.262188][ C4] x21: 000000010022da29 x20: ffffff8af72b4e80
[ 9436.262191][ C4] x19: ffffffc010023e50 x18: ffffffc010025038
[ 9436.262195][ C4] x17: 0000000000000240 x16: 0000000000000201
[ 9436.262199][ C4] x15: ffffffffffffffff x14: ffffff889f3c3100
[ 9436.262203][ C4] x13: ffffff889f3c3100 x12: 00000000049f56b8
[ 9436.262207][ C4] x11: 00000000049f56b8 x10: 00000000ffffffff
[ 9436.262212][ C4] x9 : ffffffc010023e50 x8 : dead000000000122
[ 9436.262216][ C4] x7 : ffffffffffffffff x6 : ffffffc0100239d8
[ 9436.262220][ C4] x5 : 0000000000000000 x4 : 0000000000000101
[ 9436.262223][ C4] x3 : 0000000000000080 x2 : ffffff8
---truncated---

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: PM / devfreq: Sincronizar devfreq_monitor_[start/stop] Existe la posibilidad de que un cambio frecuente del gobernador realizado en un bucle provoque corrupción en la lista de temporizadores, donde la cancelación del temporizador se realiza desde dos coloque uno de cancel_delayed_work_sync() y seguido de expire_timers() se puede ver en los rastros [1]. mientras que es verdadero, haga echo "simple_ondemand" &gt; /sys/class/devfreq/1d84000.ufshc/governor echo "rendimiento" &gt; /sys/class/devfreq/1d84000.ufshc/governor done Parece ser un problema con el controlador devfreq donde device_monitor_[start /stop] debe sincronizarse para que el trabajo retrasado se corrompa mientras está en cola, ejecutándose o cancelándose. Usemos el indicador de sondeo y el bloqueo devfreq para sincronizar la cola de la instancia del temporizador dos veces y los datos de trabajo que se corrompen. [1] ... .. -0 [003] 9436.209662: timer_cancel timer=0xffffff80444f0428 -0 [003] 9436.209664: timer_expire_entry timer=0xffffff80444f0428 now=0x10022da1c function=__typeid__ZTS FvP10timer_listE_global_addr baseclk=0x10022da1c -0 [003] 9436.209718: timer_expire_exit timer=0xffffff80444f0428 kworker/u16:6-14217 [003] 9436.209863: timer_start timer=0xffffff80444f0428 function=__typeid__ZTSFvP10timer_listE_global_addr expira = 0x10022da2b ahora = 0x10022da1c banderas = 182452227 proveedor.xxxyyy.ha-1593 [004] 9436.209888: timer_cancel temporizador=0xffffff80444f0428 proveedor.xxxyyy.ha-1593 [004] 9436.216390: timer_init temporizador=0xffffff80444f0428 proveedor.xxxyyy.ha-1593 [004] 9436.216392: timer_start temporizador=0xffffff80444f042 8 función=__typeid__ZTSFvP10timer_listE_global_addr expires=0x10022da2c ahora=0x10022da1d flags=186646532 proveedor.xxxyyy .ha-1593 [005] 9436.220992: timer_cancel timer=0xffffff80444f0428 xxxyyyTraceManag-7795 [004] 9436.261641: timer_cancel timer=0xffffff80444f0428 [2] 9436.261653][ C4] No se puede para manejar la solicitud de paginación del kernel en la dirección virtual dead00000000012a [ 9436.261664][ C4] Mem información de cancelación: [ 9436.261666][ C4] ESR = 0x96000044 [ 9436.261669][ C4] EC = 0x25: DABT (EL actual), IL = 32 bits [ 9436.261671][ C4] SET = 0, FnV = 0 [ 9436.261673][ C4 ] EA = 0, S1PTW = 0 [ 9436.261675][ C4] Información de cancelación de datos: [ 9436.261677][ C4] ISV = 0, ISS = 0x00000044 [ 9436.261680][ C4] CM = 0, WnR = 1 [ 9436.261682][ C4] [dead00000000012a] dirección entre los rangos de direcciones del usuario y del kernel [ 9436.261685][ C4] Error interno: Vaya: 96000044 [#1] SMP PREEMPT [ 9436.261701][ C4] Omitir el volcado del búfer md ftrace para: 0x3a982d0 ... [ 9436.262138][ C4 ] CPU: 4 PID: 7795 Comunicaciones: TraceManag Tainted: GSWO 5.10.149-android12-9-o-g17f915d29d0c #1 [ 9436.262141][ C4] Nombre de hardware: Qualcomm Technologies, Inc. (DT) [ 9436.262144][ C4] pstate : 22400085 (nzCv daIf +PAN -UAO +TCO BTYPE=--) [ 9436.262161][ C4] pc : expire_timers+0x9c/0x438 [ 9436.262164][ C4] lr : expire_timers+0x2a4/0x438 [ 9436.262168][ C4] sp : ffffffc010023dd0 [ 9436.262171][ C4] x29: ffffffc010023df0 x28: ffffffd0636fdc18 [ 9436.262178][ C4] x27: ffffffd063569dd0 x26: ffffffd063536008 [ 9436 .262182][ C4] x25: 0000000000000001 x24: ffffff88f7c69280 [ 9436.262185][ C4] x23: 00000000000000e0 x22: muerto000000000122 [ 9436.262188][ C4] x21: 000000010022da29 x20: ffffff8af72b4e80 [ 9436.262191][ C4] x19: ffffffc010023e50 x18: ffffffc010025038 [ 9436.262195][ C4] x 17: 0000000000000240 x16: 0000000000000201 [ 9436.262199][ C4] x15: ffffffffffffffff x14: ffffff889f3c3100 [ 9436.262203] [ C4] x13: ffffff889f3c3100 x12: 00000000049f56b8 [ 9436.262207][ C4] x11: 00000000049f56b8 x10: 00000000ffffffff [ 9436.262212][ C4] x9 : ffffffc0 10023e50 x8: muerto000000000122 [9436.262216][C4] x7: ffffffffffffffff x6: ffffffc0100239d8 [9436.262220][C4 ]---truncado---

A flaw was found in the Linux kernel resulting from race conditions and a lack of synchronization in handling the delayed work timers in the devfreq component. This issue can lead to inconsistencies and a corruption of the timer list.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
High
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
  • 2024-03-06 CVE Reserved
  • 2024-04-02 CVE Published
  • 2024-04-02 EPSS Updated
  • 2024-12-19 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-414: Missing Lock Check
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"
< 5.10.210
Search vendor "Linux" for product "Linux Kernel" and version " < 5.10.210"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 5.15.149
Search vendor "Linux" for product "Linux Kernel" and version " < 5.15.149"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 6.1.77
Search vendor "Linux" for product "Linux Kernel" and version " < 6.1.77"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 6.6.16
Search vendor "Linux" for product "Linux Kernel" and version " < 6.6.16"
en
Affected
Linux
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Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 6.7.4
Search vendor "Linux" for product "Linux Kernel" and version " < 6.7.4"
en
Affected
Linux
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Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
< 6.8
Search vendor "Linux" for product "Linux Kernel" and version " < 6.8"
en
Affected