CVE-2024-27406: lib/Kconfig.debug: TEST_IOV_ITER depends on MMU

Q: Which systems are affected in practice?

The crash affects no-MMU Linux systems when the iov_iter KUnit test is enabled and run. The reported example is qemu kc705-nommu emulation.

Q: What must happen for the crash to occur?

A local user or process must run the iov_iter unit test on a no-MMU system. The test directly calls vmap(), which is unsupported without an MMU and causes a kernel panic.

Q: Is a default runtime configuration affected?

The issue is tied to the TEST_IOV_ITER configuration option and execution of its KUnit test. The provided information does not indicate that ordinary kernel operation triggers the crash.

Q: What can be done before applying the patch?

Do not enable or run TEST_IOV_ITER on no-MMU systems. The fix makes TEST_IOV_ITER depend on MMU, preventing this unsupported test configuration.

Published May 17, 2024

Updated

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

lib/Kconfig.debug: TESTIOVITER depends on MMU

Trying to run the ioviter unit test on a nommu system such as the qemu kc705-nommu emulation results in a crash.

KTAP version 1 # Subtest: ioviter # module: kunitioviter 1..9 BUG: failure at mm/nommu.c:318/vmap()! Kernel panic - not syncing: BUG!

The test calls vmap() directly, but vmap() is not supported on nommu systems, causing the crash. TESTIOVITER therefore needs to depend on MMU.

Affected Software

7 affected components

Linux Linux kernel>=6.6<6.6.19

Linux Linux kernel>=6.7<6.7.7

Linux Linux kernel=6.8-rc1

Linux Linux kernel=6.8-rc2

Linux Linux kernel=6.8-rc3

Linux Linux kernel=6.8-rc4

Linux Linux kernel=6.8-rc5

Remediation

Event History

May 17, 2024

CVE Published

via MITRE·11:40 AM

Data Sourced

via MITRE·11:40 AM

Description

Data Sourced

via NVD·12:15 PM

RemedyDescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

Which systems are affected in practice?

The crash affects no-MMU Linux systems when the iov_iter KUnit test is enabled and run. The reported example is qemu kc705-nommu emulation.

What must happen for the crash to occur?

A local user or process must run the iov_iter unit test on a no-MMU system. The test directly calls vmap(), which is unsupported without an MMU and causes a kernel panic.

Is a default runtime configuration affected?

The issue is tied to the TEST_IOV_ITER configuration option and execution of its KUnit test. The provided information does not indicate that ordinary kernel operation triggers the crash.

What can be done before applying the patch?

Do not enable or run TEST_IOV_ITER on no-MMU systems. The fix makes TEST_IOV_ITER depend on MMU, preventing this unsupported test configuration.

CVE-2024-27406: lib/Kconfig.debug: TEST_IOV_ITER depends on MMU

Affected Software

Remediation

Patch Available

Patch Available

Patch Available

Event History

Frequently Asked Questions

Which systems are affected in practice?

What must happen for the crash to occur?

Is a default runtime configuration affected?

What can be done before applying the patch?

Company

Resources

Contact

Frequently Asked Questions

Which systems are affected in practice?

What must happen for the crash to occur?

Is a default runtime configuration affected?

What can be done before applying the patch?