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.
CVSS Details
- CVSS 3.1 Base Score: 7.1
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | Upgrade linux | Jul 27, 2026 | Jul 27, 2026 |
| Redhat_linux | — | No solution exists | Jul 9, 2025 | May 21, 2024 |
| Suse | — | Upgrade dtb-mediatekUpgrade dtb-xilinxUpgrade kernel-default-base-rebuildUpgrade kernel-rt_debug-livepatch-develUpgrade kernel-default-baseUpgrade reiserfs-kmp-rtUpgrade dlm-kmp-azureUpgrade kernel-defaultUpgrade cluster-md-kmp-defaultUpgrade ocfs2-kmp-rtUpgrade kernel-symsUpgrade kernel-rt-livepatch-develUpgrade dtb-amlogicUpgrade dtb-sprdUpgrade reiserfs-kmp-defaultUpgrade kernel-rt_debugUpgrade kernel-rt_debug-vdsoUpgrade kernel-obs-qaUpgrade kernel-debug-livepatch-develUpgrade kernel-devel-rtUpgrade kernel-64kb-extraUpgrade kernel-64kb-develUpgrade kernel-macrosUpgrade kernel-rt-develUpgrade kernel-syms-rtUpgrade kselftests-kmp-defaultUpgrade dtb-renesasUpgrade kernel-azure-vdsoUpgrade kernel-docsUpgrade dtb-apmUpgrade dtb-amdUpgrade dtb-socionextUpgrade dtb-rockchipUpgrade kernel-rt-extraUpgrade dlm-kmp-rtUpgrade kselftests-kmp-rtUpgrade reiserfs-kmp-azureUpgrade dtb-armUpgrade kernel-default-livepatch-develUpgrade cluster-md-kmp-64kbUpgrade kernel-default-extraUpgrade dtb-nvidiaUpgrade dlm-kmp-defaultUpgrade kernel-rt-vdsoUpgrade dtb-qcomUpgrade kernel-debug-develUpgrade kernel-default-livepatchUpgrade ocfs2-kmp-64kbUpgrade kernel-syms-azureUpgrade kernel-64kb-optionalUpgrade kernel-64kb-livepatch-develUpgrade dtb-marvellUpgrade kernel-zfcpdumpUpgrade dtb-broadcomUpgrade dtb-exynosUpgrade dtb-amazonUpgrade kernel-azure-extraUpgrade dtb-hisiliconUpgrade kernel-source-rtUpgrade kernel-azure-livepatch-develUpgrade dtb-appleUpgrade cluster-md-kmp-rtUpgrade kernel-source-azureUpgrade kernel-kvmsmall-vdsoUpgrade kernel-debugUpgrade kernel-azureUpgrade kernel-64kbUpgrade kernel-develUpgrade gfs2-kmp-rtUpgrade gfs2-kmp-64kbUpgrade dtb-lgUpgrade cluster-md-kmp-azureUpgrade kernel-sourceUpgrade kernel-kvmsmallUpgrade reiserfs-kmp-64kbUpgrade ocfs2-kmp-azureUpgrade gfs2-kmp-azureUpgrade kernel-kvmsmall-livepatch-develUpgrade kernel-rtUpgrade kernel-rt_debug-develUpgrade kernel-default-develUpgrade dtb-caviumUpgrade dtb-allwinnerUpgrade kselftests-kmp-64kbUpgrade ocfs2-kmp-defaultUpgrade dtb-freescaleUpgrade kernel-source-vanillaUpgrade dtb-alteraUpgrade kselftests-kmp-azureUpgrade kernel-kvmsmall-develUpgrade kernel-rt-optionalUpgrade kernel-docs-htmlUpgrade kernel-default-optionalUpgrade kernel-default-vdsoUpgrade kernel-obs-buildUpgrade kernel-devel-azureUpgrade kernel-azure-develUpgrade gfs2-kmp-defaultUpgrade kernel-debug-vdsoUpgrade kernel-azure-optionalUpgrade dlm-kmp-64kb | Aug 9, 2024 | May 21, 2024 |
| Ubuntu | — | Upgrade linux-nvidia-6.5 | Nov 19, 2024 | May 21, 2024 |
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