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 gfs2-kmp-azureUpgrade kernel-64kb-livepatch-develUpgrade kernel-sourceUpgrade ocfs2-kmp-azureUpgrade kernel-syms-azureUpgrade ocfs2-kmp-64kbUpgrade kernel-azure-optionalUpgrade dtb-allwinnerUpgrade dtb-marvellUpgrade gfs2-kmp-defaultUpgrade dtb-broadcomUpgrade kernel-debug-vdsoUpgrade dlm-kmp-64kbUpgrade dtb-amazonUpgrade kernel-rt-vdsoUpgrade dtb-caviumUpgrade dtb-alteraUpgrade kernel-source-vanillaUpgrade kselftests-kmp-azureUpgrade dtb-freescaleUpgrade kernel-rt-optionalUpgrade kselftests-kmp-64kbUpgrade ocfs2-kmp-defaultUpgrade kernel-zfcpdumpUpgrade kernel-default-optionalUpgrade kernel-default-vdsoUpgrade kernel-azure-develUpgrade kernel-docs-htmlUpgrade kernel-azureUpgrade kernel-kvmsmall-develUpgrade dtb-exynosUpgrade kernel-rt_debug-develUpgrade dtb-appleUpgrade dtb-lgUpgrade kernel-azure-livepatch-develUpgrade reiserfs-kmp-64kbUpgrade kernel-default-livepatchUpgrade kernel-source-azureUpgrade gfs2-kmp-64kbUpgrade kernel-kvmsmallUpgrade kernel-kvmsmall-livepatch-develUpgrade kernel-obs-buildUpgrade dtb-hisiliconUpgrade dtb-qcomUpgrade kernel-debug-develUpgrade kernel-source-rtUpgrade kernel-default-develUpgrade kernel-devel-azureUpgrade kernel-64kb-optionalUpgrade kernel-develUpgrade kernel-debugUpgrade kernel-kvmsmall-vdsoUpgrade cluster-md-kmp-azureUpgrade gfs2-kmp-rtUpgrade kernel-64kbUpgrade cluster-md-kmp-rtUpgrade kernel-rtUpgrade kernel-azure-extraUpgrade dtb-renesasUpgrade kernel-macrosUpgrade kernel-docsUpgrade dtb-amdUpgrade dlm-kmp-azureUpgrade kernel-default-livepatch-develUpgrade dlm-kmp-defaultUpgrade cluster-md-kmp-64kbUpgrade dtb-armUpgrade kernel-symsUpgrade kernel-rt-livepatch-develUpgrade kernel-default-extraUpgrade kernel-default-baseUpgrade reiserfs-kmp-rtUpgrade kernel-rt-develUpgrade reiserfs-kmp-azureUpgrade cluster-md-kmp-defaultUpgrade kernel-obs-qaUpgrade dlm-kmp-rtUpgrade reiserfs-kmp-defaultUpgrade ocfs2-kmp-rtUpgrade kernel-rt_debugUpgrade kernel-debug-livepatch-develUpgrade kernel-azure-vdsoUpgrade dtb-sprdUpgrade dtb-amlogicUpgrade kernel-rt_debug-vdsoUpgrade kselftests-kmp-rtUpgrade kernel-default-base-rebuildUpgrade dtb-xilinxUpgrade kernel-rt_debug-livepatch-develUpgrade kernel-64kb-extraUpgrade kernel-rt-extraUpgrade kselftests-kmp-defaultUpgrade kernel-syms-rtUpgrade dtb-socionextUpgrade dtb-apmUpgrade kernel-64kb-develUpgrade dtb-mediatekUpgrade dtb-nvidiaUpgrade kernel-devel-rtUpgrade kernel-defaultUpgrade dtb-rockchip | Aug 9, 2024 | May 21, 2024 |
| Ubuntu | — | Upgrade linux-nvidia-6.5 | Nov 19, 2024 | May 21, 2024 |
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub