CVE-2023-52597
KVM: s390: fix setting of fpc register
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: fix setting of fpc register
kvm_arch_vcpu_ioctl_set_fpu() allows to set the floating point control
(fpc) register of a guest cpu. The new value is tested for validity by
temporarily loading it into the fpc register.
This may lead to corruption of the fpc register of the host process:
if an interrupt happens while the value is temporarily loaded into the fpc
register, and within interrupt context floating point or vector registers
are used, the current fp/vx registers are saved with save_fpu_regs()
assuming they belong to user space and will be loaded into fp/vx registers
when returning to user space.
test_fp_ctl() restores the original user space / host process fpc register
value, however it will be discarded, when returning to user space.
In result the host process will incorrectly continue to run with the value
that was supposed to be used for a guest cpu.
Fix this by simply removing the test. There is another test right before
the SIE context is entered which will handles invalid values.
This results in a change of behaviour: invalid values will now be accepted
instead of that the ioctl fails with -EINVAL. This seems to be acceptable,
given that this interface is most likely not used anymore, and this is in
addition the same behaviour implemented with the memory mapped interface
(replace invalid values with zero) - see sync_regs() in kvm-s390.c.
En el kernel de Linux, se resolvió la siguiente vulnerabilidad: KVM: s390: configuración fija del registro fpc kvm_arch_vcpu_ioctl_set_fpu() permite configurar el registro de control de punto flotante (fpc) de una CPU invitada. Se prueba la validez del nuevo valor cargándolo temporalmente en el registro fpc. Esto puede conducir a la corrupción del registro fpc del proceso host: si ocurre una interrupción mientras el valor se carga temporalmente en el registro fpc, y dentro del contexto de interrupción se utilizan registros de punto flotante o vectoriales, los registros fp/vx actuales se guardan con save_fpu_regs() suponiendo que pertenecen al espacio del usuario y se cargarán en los registros fp/vx cuando regresen al espacio del usuario. test_fp_ctl() restaura el valor de registro fpc del proceso de host/espacio de usuario original; sin embargo, se descartará al regresar al espacio de usuario. Como resultado, el proceso del host continuará ejecutándose incorrectamente con el valor que se suponía que debía usarse para una CPU invitada. Solucione este problema simplemente quitando la prueba. Hay otra prueba justo antes de ingresar al contexto SIE que manejará valores no válidos. Esto da como resultado un cambio de comportamiento: ahora se aceptarán valores no válidos en lugar de que el ioctl falle con -EINVAL. Esto parece aceptable, dado que lo más probable es que esta interfaz ya no se use y, además, este es el mismo comportamiento implementado con la interfaz asignada en memoria (reemplace los valores no válidos con cero); consulte sync_regs() en kvm-s390.c.
CVSS Scores
SSVC
- Decision:Track
Timeline
- 2024-03-02 CVE Reserved
- 2024-03-06 CVE Published
- 2024-03-06 EPSS Updated
- 2024-08-02 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
- CWE-20: Improper Input Validation
CAPEC
References (11)
URL | Date | SRC |
---|
URL | Date | SRC |
---|---|---|
https://access.redhat.com/security/cve/CVE-2023-52597 | 2024-05-22 | |
https://bugzilla.redhat.com/show_bug.cgi?id=2268311 | 2024-05-22 |
Affected Vendors, Products, and Versions
Vendor | Product | Version | Other | Status | ||||||
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Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | < 4.19.307 Search vendor "Linux" for product "Linux Kernel" and version " < 4.19.307" | en |
Affected
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Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | < 5.4.269 Search vendor "Linux" for product "Linux Kernel" and version " < 5.4.269" | en |
Affected
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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
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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
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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
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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
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Linux Search vendor "Linux" | 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
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Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | < 6.8 Search vendor "Linux" for product "Linux Kernel" and version " < 6.8" | en |
Affected
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