VULNERABILITY INTELLIGENCE
CVE-2024-35801
Description
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.
Weakness classification
- nvd@nist.gov: NVD-CWE-noinfo
- 134c704f-9b21-4f2e-91b3-4a467353bcc0: CWE-416
Primary references
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — Patch
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — Patch
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — Patch
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — Patch
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67 — Patch
- af854a3a-2127-422b-91ae-364da2661108 — Patch
- af854a3a-2127-422b-91ae-364da2661108 — Patch
- af854a3a-2127-422b-91ae-364da2661108 — Patch
- af854a3a-2127-422b-91ae-364da2661108 — Patch
- af854a3a-2127-422b-91ae-364da2661108 — Patch