Description (CNA)
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 (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 672365477ae8afca5a1cca98c1deb733235e4525 before 21c7c00dae55cb0e3810d5f9506b58f68475d41d; affected 672365477ae8afca5a1cca98c1deb733235e4525 before 1acbca933313aa866e39996904c9aca4d435c4cd; affected 672365477ae8afca5a1cca98c1deb733235e4525 before 92b0f04e937665bde5768f3fcc622dcce44413d8; affected 672365477ae8afca5a1cca98c1deb733235e4525 before b61e3b7055ac6edee4be071c52f48c26472d2624; affected 672365477ae8afca5a1cca98c1deb733235e4525 before 10e4b5166df9ff7a2d5316138ca668b42d004422 |
| Linux / Linux | affected 5.16; unaffected 0 before 5.16; unaffected 6.1.84 through 6.1.*; unaffected 6.6.24 through 6.6.*; unaffected 6.7.12 through 6.7.*; unaffected 6.8.3 through 6.8.*; unaffected 6.9 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/21c7c00dae55cb0e3810d5f9506b58f68475d41d
- https://git.kernel.org/stable/c/1acbca933313aa866e39996904c9aca4d435c4cd
- https://git.kernel.org/stable/c/92b0f04e937665bde5768f3fcc622dcce44413d8
- https://git.kernel.org/stable/c/b61e3b7055ac6edee4be071c52f48c26472d2624
- https://git.kernel.org/stable/c/10e4b5166df9ff7a2d5316138ca668b42d004422
ADP enrichment
No English description supplied.
No references supplied.
No English description supplied.
- https://git.kernel.org/stable/c/21c7c00dae55cb0e3810d5f9506b58f68475d41d
- https://git.kernel.org/stable/c/1acbca933313aa866e39996904c9aca4d435c4cd
- https://git.kernel.org/stable/c/92b0f04e937665bde5768f3fcc622dcce44413d8
- https://git.kernel.org/stable/c/b61e3b7055ac6edee4be071c52f48c26472d2624
- https://git.kernel.org/stable/c/10e4b5166df9ff7a2d5316138ca668b42d004422