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CVE PROGRAM SOURCE RECORD7.8 High

CVE-2024-35801

x86/fpu: Keep xfd_state in sync with MSR_IA32_XFD

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Status
Published
Published
Updated
Assigning organization
Linux

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • 672365477ae8afca5a1cca98c1deb733235e4525 to < 21c7c00dae55cb0e3810d5f9506b58f68475d41daffected
  • 672365477ae8afca5a1cca98c1deb733235e4525 to < 1acbca933313aa866e39996904c9aca4d435c4cdaffected
  • 672365477ae8afca5a1cca98c1deb733235e4525 to < 92b0f04e937665bde5768f3fcc622dcce44413d8affected
  • 672365477ae8afca5a1cca98c1deb733235e4525 to < b61e3b7055ac6edee4be071c52f48c26472d2624affected
  • 672365477ae8afca5a1cca98c1deb733235e4525 to < 10e4b5166df9ff7a2d5316138ca668b42d004422affected

Linux Linux

Default version status: affected

  • 5.16affected
  • 0 to < 5.16unaffected
  • 6.1.84 to ≤ 6.1.*unaffected
  • 6.6.24 to ≤ 6.6.*unaffected
  • 6.7.12 to ≤ 6.7.*unaffected
  • 6.8.3 to ≤ 6.8.*unaffected
  • 6.9 to ≤ *unaffected

References