CVE-2024-46794: x86/tdx: Fix data leak in mmio_read()

Severity: low (CVSS 3.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-09-18 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: x86/tdx: Fix data leak in mmio_read() The mmio_read() function makes a TDVMCALL to retrieve MMIO data for an address from the VMM. Sean noticed that mmio_read() unintentionally exposes the value of an initialized variable (val) on the stack to the VMM. This variable is only needed as an output value. It did not need to be passed to the VMM in the first place. Do not send the original value of *val to the VMM. [ dhansen: clarify what 'val' is used for. ]

Affected products

Linux kernel: through 5.19; from 6.1 before 6.1.110; from 6.6 before 6.6.51; from 6.10 before 6.10.10; 6.11-rc1, 6.11-rc2, 6.11-rc3, 6.11-rc4, 6.11-rc5, 6.11-rc6 — fixed in 6.1.110, 6.10.10, 6.6.51

How to fix

Upgrade to a fixed version: Linux kernel 6.1.110, 6.10.10, 6.6.51. Check the vendor advisory for mitigations.

References

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