cbcvebase.
CVE-2023-52874
published 2024-05-21

CVE-2023-52874: In the Linux kernel, the following vulnerability has been resolved: x86/tdx: Zero out the missing RSI in TDX_HYPERCALL macro In the TDX_HYPERCALL asm, after…

PriorityP423medium5.5CVSS 3.1
AVLACLPRLUINSUCHINAN
EPSS
0.25%
16.9th percentile
In the Linux kernel, the following vulnerability has been resolved: x86/tdx: Zero out the missing RSI in TDX_HYPERCALL macro In the TDX_HYPERCALL asm, after the TDCALL instruction returns from the untrusted VMM, the registers that the TDX guest shares to the VMM need to be cleared to avoid speculative execution of VMM-provided values. RSI is specified in the bitmap of those registers, but it is missing when zeroing out those registers in the current TDX_HYPERCALL. It was there when it was originally added in commit 752d13305c78 ("x86/tdx: Expand __tdx_hypercall() to handle more arguments"), but was later removed in commit 1e70c680375a ("x86/tdx: Do not corrupt frame-pointer in __tdx_hypercall()"), which was correct because %rsi is later restored in the "pop %rsi". However a later commit 7a3a401874be ("x86/tdx: Drop flags from __tdx_hypercall()") removed that "pop %rsi" but forgot to add the "xor %rsi, %rsi" back. Fix by adding it back.

Affected

9 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.6.8-1 (forky)linux 6.6.8-1 (forky)
linuxlinux
linuxlinux>= 7a3a401874bea02f568aa416ac29170d8cde0dc2 < 2191950d35d8f81620ea8d4e04d983f664fe3a8a2191950d35d8f81620ea8d4e04d983f664fe3a8a
linuxlinux>= 7a3a401874bea02f568aa416ac29170d8cde0dc2 < de4c5bacca4f50233f1f791bec9eeb4dee1b14cdde4c5bacca4f50233f1f791bec9eeb4dee1b14cd
linuxlinux>= 7a3a401874bea02f568aa416ac29170d8cde0dc2 < 5d092b66119d774853cc9308522620299048a6625d092b66119d774853cc9308522620299048a662
linuxlinux_kernel>= 0 < 6.6.8-16.6.8-1
linuxlinux_kernel>= 0 < 6.6.8-16.6.8-1
linuxlinux_kernel>= 6.4 < 6.5.126.5.12
linuxlinux_kernel>= 6.6 < 6.6.26.6.2

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
osv5.5MEDIUM
vendor_debian5.5LOW
vendor_redhat5.5MEDIUM
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