CVE-2026-22991: libceph: make free_choose_arg_map() resilient to partial allocation

Published Jan 23, 2026
·
Updated

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

libceph: make freechooseargmap() resilient to partial allocation

freechooseargmap() may dereference a NULL pointer if its caller fails after a partial allocation.

For example, in decodechooseargs(), if allocation of argmap->args fails, execution jumps to the fail label and freechooseargmap() is called. Since argmap->size is updated to a non-zero value before memory allocation, freechooseargmap() will iterate over argmap->args and dereference a NULL pointer.

To prevent this potential NULL pointer dereference and make freechooseargmap() more resilient, add checks for pointers before iterating.

Affected Software

12 affected componentsFixes available
linux/kernel
Linux Linux kernel>=4.13<5.10.248
Linux Linux kernel>=5.11<5.15.198
Linux Linux kernel>=5.16<6.1.161
Linux Linux kernel>=6.2<6.6.121
Linux Linux kernel>=6.7<6.12.66
Linux Linux kernel>=6.13<6.18.6
Linux Linux kernel=6.19-rc1
Linux Linux kernel=6.19-rc2
Linux Linux kernel=6.19-rc3
Linux Linux kernel=6.19-rc4
Microsoft cbl2 kernel 5.15.186.1-1

Event History

Jan 23, 2026
CVE Published
via MITRE·03:24 PM
Data Sourced
via MITRE·03:24 PM
DescriptionSeverity
Data Sourced
via NVD·04:15 PM
RemedyDescriptionSeverityWeaknessAffected Software
Feb 28, 2026
Data Sourced
via Microsoft·09:04 AM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·09:04 AM
Affected Software
Updated
via Microsoft·09:04 AM
DescriptionSeverity

Frequently Asked Questions

1

What is the severity of CVE-2026-22991?

CVE-2026-22991 has a severity that warrants serious attention due to its potential to cause NULL pointer dereferences.

2

How do I fix CVE-2026-22991?

To fix CVE-2026-22991, ensure you update your Linux kernel to the latest patched version.

3

Which software is affected by CVE-2026-22991?

CVE-2026-22991 affects the Linux kernel, specifically components related to libceph.

4

What are the potential consequences of CVE-2026-22991?

Exploitation of CVE-2026-22991 may lead to denial of service due to unexpected application crashes.

5

When was CVE-2026-22991 disclosed?

CVE-2026-22991 was disclosed as part of ongoing security updates in the Linux kernel.

Contact

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