CVE-2024-35801

In the Linux kernel, the following vulnerability has been resolved: x86/fpu: Keep xfd_state in sync with MSR_IA32_XFD Commit 672365477ae8 ("x86/fpu: Update XFD state where required") and commit 8bf26758ca96 ("x86/fpu: Add XFD state to fpstate") introduced a per CPU variable xfd_state to keep the MSR_IA32_XFD value cached, in order to avoid unnecessary writes to the MSR. On CPU hotplug MSR_IA32_XFD is reset to the init_fpstate.xfd, which wipes out any stale state. But the per CPU cached xfd value is not reset, which brings them out of sync. As a consequence a subsequent xfd_update_state() might fail to update the MSR which in turn can result in XRSTOR raising a #NM in kernel space, which crashes the kernel. To fix this, introduce xfd_set_state() to write xfd_state together with MSR_IA32_XFD, and use it in all places that set MSR_IA32_XFD.
Configurations

No configuration.

History

21 Nov 2024, 09:20

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/10e4b5166df9ff7a2d5316138ca668b42d004422 - () https://git.kernel.org/stable/c/10e4b5166df9ff7a2d5316138ca668b42d004422 -
References () https://git.kernel.org/stable/c/1acbca933313aa866e39996904c9aca4d435c4cd - () https://git.kernel.org/stable/c/1acbca933313aa866e39996904c9aca4d435c4cd -
References () https://git.kernel.org/stable/c/21c7c00dae55cb0e3810d5f9506b58f68475d41d - () https://git.kernel.org/stable/c/21c7c00dae55cb0e3810d5f9506b58f68475d41d -
References () https://git.kernel.org/stable/c/92b0f04e937665bde5768f3fcc622dcce44413d8 - () https://git.kernel.org/stable/c/92b0f04e937665bde5768f3fcc622dcce44413d8 -
References () https://git.kernel.org/stable/c/b61e3b7055ac6edee4be071c52f48c26472d2624 - () https://git.kernel.org/stable/c/b61e3b7055ac6edee4be071c52f48c26472d2624 -

03 Jul 2024, 02:02

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: x86/fpu: mantenga xfd_state sincronizado con MSR_IA32_XFD Confirme 672365477ae8 ("x86/fpu: actualice el estado de XFD cuando sea necesario") y confirme 8bf26758ca96 ("x86/fpu: agregue el estado de XFD a fpstate") introdujo una variable xfd_state por CPU para mantener el valor MSR_IA32_XFD en caché, a fin de evitar escrituras innecesarias en el MSR. En la conexión en caliente de la CPU, MSR_IA32_XFD se restablece a init_fpstate.xfd, lo que elimina cualquier estado obsoleto. Pero el valor xfd almacenado en caché por CPU no se restablece, lo que los desincroniza. Como consecuencia, un xfd_update_state() posterior podría no actualizar el MSR, lo que a su vez puede provocar que XRSTOR genere un #NM en el espacio del kernel, lo que bloquea el kernel. Para solucionar este problema, introduzca xfd_set_state() para escribir xfd_state junto con MSR_IA32_XFD y utilícelo en todos los lugares que configuren MSR_IA32_XFD.
CWE CWE-416
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.8

17 May 2024, 18:35

Type Values Removed Values Added
New CVE

Information

Published : 2024-05-17 14:15

Updated : 2024-11-21 09:20


NVD link : CVE-2024-35801

Mitre link : CVE-2024-35801

CVE.ORG link : CVE-2024-35801


JSON object : View

Products Affected

No product.

CWE
CWE-416

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