CVE-2024-26670

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Source

https://nvd.nist.gov/vuln/detail/CVE-2024-26670

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-26670.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2024-26670

Related

Published

2024-04-02T07:15:43Z

Modified

2024-09-18T03:26:01.008099Z

Summary

[none]

Details

In the Linux kernel, the following vulnerability has been resolved:

arm64: entry: fix ARM64WORKAROUNDSPECULATIVEUNPRIVLOAD

Currently the ARM64WORKAROUNDSPECULATIVEUNPRIVLOAD workaround isn't quite right, as it is supposed to be applied after the last explicit memory access, but is immediately followed by an LDR.

The ARM64WORKAROUNDSPECULATIVEUNPRIVLOAD workaround is used to handle Cortex-A520 erratum 2966298 and Cortex-A510 erratum 3117295, which are described in:

https://developer.arm.com/documentation/SDEN2444153/0600/?lang=en
https://developer.arm.com/documentation/SDEN1873361/1600/?lang=en

In both cases the workaround is described as:

| If pagetable isolation is disabled, the context switch logic in the | kernel can be updated to execute the following sequence on affected | cores before exiting to EL0, and after all explicit memory accesses: | | 1. A non-shareable TLBI to any context and/or address, including | unused contexts or addresses, such as a TLBI VALE1 Xzr. | | 2. A DSB NSH to guarantee completion of the TLBI.

The important part being that the TLBI+DSB must be placed "after all explicit memory accesses".

Unfortunately, as-implemented, the TLBI+DSB is immediately followed by an LDR, as we have:

This patch fixes this by reworking the logic to place the TLBI+DSB immediately before the ERET, after all explicit memory accesses.

The ERET is currently in a separate alternative block, and alternatives cannot be nested. To account for this, the alternative block for ARM64UNMAPKERNELATEL0 is replaced with a single alternative branch to skip the KPTI logic, with the new shape of the logic being:

The new structure means that the workaround is only applied when KPTI is not in use; this is fine as noted in the documented implications of the erratum:

| Pagetable isolation between EL0 and higher level ELs prevents the | issue from occurring.

... and as per the workaround description quoted above, the workaround is only necessary "If pagetable isolation is disabled".

References

Affected packages

Debian:12 / linux

Package

Name: linux
Purl: pkg:deb/debian/linux?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

6.*

6.1.27-1

6.1.37-1

6.1.38-1

6.1.38-2~bpo11+1

6.1.38-2

6.1.38-3

6.1.38-4~bpo11+1

6.1.38-4

6.1.52-1

6.1.55-1~bpo11+1

6.1.55-1

6.1.64-1

6.1.66-1

6.1.67-1

6.1.69-1~bpo11+1

6.1.69-1

6.1.76-1~bpo11+1

6.1.76-1

6.1.82-1

6.1.85-1

6.1.90-1~bpo11+1

6.1.90-1

6.1.94-1~bpo11+1

6.1.94-1

6.1.98-1

6.1.99-1

6.1.106-1

6.1.106-2

6.1.106-3

6.3.1-1~exp1

6.3.2-1~exp1

6.3.4-1~exp1

6.3.5-1~exp1

6.3.7-1~bpo12+1

6.3.7-1

6.3.11-1

6.4~rc6-1~exp1

6.4~rc7-1~exp1

6.4.1-1~exp1

6.4.4-1~bpo12+1

6.4.4-1

6.4.4-2

6.4.4-3~bpo12+1

6.4.4-3

6.4.11-1

6.4.13-1

6.5~rc4-1~exp1

6.5~rc6-1~exp1

6.5~rc7-1~exp1

6.5.1-1~exp1

6.5.3-1~bpo12+1

6.5.3-1

6.5.6-1

6.5.8-1

6.5.10-1~bpo12+1

6.5.10-1

6.5.13-1

6.6.3-1~exp1

6.6.4-1~exp1

6.6.7-1~exp1

6.6.8-1

6.6.9-1

6.6.11-1

6.6.13-1~bpo12+1

6.6.13-1

6.6.15-1

6.6.15-2

6.7-1~exp1

6.7.1-1~exp1

6.7.4-1~exp1

6.7.7-1

6.7.9-1

6.7.9-2

6.7.12-1~bpo12+1

6.7.12-1

6.8.9-1

6.8.11-1

6.8.12-1~bpo12+1

6.8.12-1

6.9.2-1~exp1

6.9.7-1~bpo12+1

6.9.7-1

6.9.8-1

6.9.9-1

6.9.10-1~bpo12+1

6.9.10-1

6.9.11-1

6.9.12-1

6.10-1~exp1

6.10.1-1~exp1

6.10.3-1

6.10.4-1

6.10.6-1~bpo12+1

6.10.6-1

6.10.7-1

6.10.9-1

6.11~rc4-1~exp1

6.11~rc5-1~exp1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:13 / linux