Описание
In the Linux kernel, the following vulnerability has been resolved:
platform/x86/amd/pmc: Propagate SMU errors and validate S2D address
amd_stb_s2d_init() discards the return value of several S2D SMU commands.
When the SMU refuses a command (e.g. "SMU cmd failed. err: 0xff") the
failure is only noticed indirectly - if at all - and reported as -EIO,
masking the real error.
More seriously, the S2D_PHYS_ADDR_LOW/HIGH return values are ignored, so
on failure phys_addr_low/hi are left uninitialised and the assembled
address is passed straight to devm_ioremap(). When the SMU leaves them at
zero this maps physical address 0 and trips the ioremap-on-RAM warning:
amd_pmc AMDI000B:00: SMU cmd failed. err: 0xff
ioremap on RAM at 0x0000000000000000 - 0x0000000000ffffff
WARNING: CPU: 13 PID: 4592 at arch/x86/mm/ioremap.c:...
Check the return value of each SMU command and propagate it, and reject a
zero physical address before calling devm_ioremap().
A flaw was found in the Linux kernel. Specifically, within the AMD Platform Management Controller (PMC) component, the amd_stb_s2d_init() function does not properly validate memory addresses returned by System Management Unit (SMU) commands. This can result in the kernel attempting to map a critical memory region at address zero, leading to system warnings and potential instability. This issue could be exploited by a local attacker to cause a denial of service.
Отчет
A flaw was found in the Linux kernel AMD Platform Management Controller (PMC) driver. In amd_stb_s2d_init(), the return values of several Spill-to-DRAM (S2D) SMU commands are discarded, so when the SMU refuses a command the failure is only noticed indirectly and masked as a generic -EIO, and the S2D_PHYS_ADDR_LOW/HIGH values are left uninitialized. The resulting physical address is passed directly to devm_ioremap(), which can map physical address 0 and trigger an ioremap-on-RAM warning and potential kernel panic. A local attacker could leverage this flaw to cause a denial of service. Red Hat rated this flaw as Moderate severity (CVSS 5.5, AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H); the upstream CVEORG score of 7.7 (AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H) differs because it assumes no privileges are required and a high confidentiality impact, whereas the technical evidence for this flaw shows it requires local access and affects only availability. The kernel in Red Hat Enterprise Linux 9 and Red Hat Enterprise Linux 10, and the RHEL 9-based RHCOS 9 components shipped in OpenShift Container Platform 4.13 and later, are affected. The fix is currently deferred for these affected streams because Red Hat does not file trackers for MODERATE severity flaws whose CVSS score is below 7.0; the residual risk is that on an affected AMD platform whose SMU refuses S2D commands, the unvalidated address passed to devm_ioremap() can lead to a kernel warning or panic, resulting in local denial of service. Red Hat Enterprise Linux 6, 7, and 8 kernels (including kernel-rt) and the RHEL 8-based RHCOS 8 component shipped in OpenShift Container Platform 4.12 are not affected because the vulnerable code is not present in those kernels.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Fix deferred |
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Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: platform/x86/amd/pmc: Propagate SMU errors and validate S2D address amd_stb_s2d_init() discards the return value of several S2D SMU commands. When the SMU refuses a command (e.g. "SMU cmd failed. err: 0xff") the failure is only noticed indirectly - if at all - and reported as -EIO, masking the real error. More seriously, the S2D_PHYS_ADDR_LOW/HIGH return values are ignored, so on failure phys_addr_low/hi are left uninitialised and the assembled address is passed straight to devm_ioremap(). When the SMU leaves them at zero this maps physical address 0 and trips the ioremap-on-RAM warning: amd_pmc AMDI000B:00: SMU cmd failed. err: 0xff ioremap on RAM at 0x0000000000000000 - 0x0000000000ffffff WARNING: CPU: 13 PID: 4592 at arch/x86/mm/ioremap.c:... Check the return value of each SMU command and propagate it, and reject a zero physical address before calling devm_ioremap().
In the Linux kernel, the following vulnerability has been resolved: platform/x86/amd/pmc: Propagate SMU errors and validate S2D address amd_stb_s2d_init() discards the return value of several S2D SMU commands. When the SMU refuses a command (e.g. "SMU cmd failed. err: 0xff") the failure is only noticed indirectly - if at all - and reported as -EIO, masking the real error. More seriously, the S2D_PHYS_ADDR_LOW/HIGH return values are ignored, so on failure phys_addr_low/hi are left uninitialised and the assembled address is passed straight to devm_ioremap(). When the SMU leaves them at zero this maps physical address 0 and trips the ioremap-on-RAM warning: amd_pmc AMDI000B:00: SMU cmd failed. err: 0xff ioremap on RAM at 0x0000000000000000 - 0x0000000000ffffff WARNING: CPU: 13 PID: 4592 at arch/x86/mm/ioremap.c:... Check the return value of each SMU command and propagate it, and reject a zero physical address before calling devm_ioremap().
In the Linux kernel, the following vulnerability has been resolved: p ...
In the Linux kernel, the following vulnerability has been resolved: platform/x86/amd/pmc: Propagate SMU errors and validate S2D address amd_stb_s2d_init() discards the return value of several S2D SMU commands. When the SMU refuses a command (e.g. "SMU cmd failed. err: 0xff") the failure is only noticed indirectly - if at all - and reported as -EIO, masking the real error. More seriously, the S2D_PHYS_ADDR_LOW/HIGH return values are ignored, so on failure phys_addr_low/hi are left uninitialised and the assembled address is passed straight to devm_ioremap(). When the SMU leaves them at zero this maps physical address 0 and trips the ioremap-on-RAM warning: amd_pmc AMDI000B:00: SMU cmd failed. err: 0xff ioremap on RAM at 0x0000000000000000 - 0x0000000000ffffff WARNING: CPU: 13 PID: 4592 at arch/x86/mm/ioremap.c:... Check the return value of each SMU command and propagate it, and reject a zero physical address before calling devm_ioremap().
ELSA-2026-500572: Unbreakable Enterprise kernel security update (IMPORTANT)
EPSS
5.5 Medium
CVSS3