NVD / CVE Program· CNA Linux

CVE-2022-49647: cgroup: Use separate src/dst nodes when preloading css_sets for migration

Noroxi assessment

Priority: Monitor (action score 31/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.28% (FIRST EPSS).
Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 05f7658210d1d331e8dd4cb6e7bbbe3df5f5ac27, 07fd5b6cdf3cc30bfde8fe0f644771688be04447, 0e41774b564befa6d271e8d5086bf870d617a4e6.

Low priority for now. Upgrade to Linux Linux 05f7658210d1d331e8dd4cb6e7bbbe3df5f5ac27, 07fd5b6cdf3cc30bfde8fe0f644771688be04447, 0e41774b564befa6d271e8d5086bf870d617a4e6 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: cgroup: Use separate src/dst nodes when preloading css_sets for migration Each cset (css_set) is pinned by its tasks. When we're moving tasks around across csets for a migration, we need to hold the source and destination csets to ensure that they don't go away while we're moving tasks about. This is done by linking cset->mg_preload_node on either the mgctx->preloaded_src_csets or mgctx->preloaded_dst_csets list. Using the same cset->mg_preload_node for both the src and dst lists was deemed okay as a cset can't be both the source and destination at the same time. Unfortunately, this overloading becomes problematic when multiple tasks are involved in a migration and some of them are identity noop migrations while others are actually moving across cgroups. For example, this can happen with the following sequence on cgroup1: #1> mkdir -p /sys/fs/cgroup/misc/a/b #2> echo $$ > /sys/fs/cgroup/misc/a/cgroup.procs #3> RUN_A_COMMAND_WHICH_CREATES_MULTIPLE_THREADS & #4> PID=$! #5> echo $PID > /sys/fs/cgroup/misc/a/b/tasks #6> echo $PID > /sys/fs/cgroup/misc/a/cgroup.procs the process including the group leader back into a. In this final migration, non-leader threads would be doing identity migration while the group leader is doing an actual one. After #3, let's say the whole process was in cset A, and that after #4, the leader moves to cset B. Then, during #6, the following happens: 1. cgroup_migrate_add_src() is called on B for the leader. 2. cgroup_migrate_add_src() is called on A for the other threads. 3. cgroup_migrate_prepare_dst() is called. It scans the src list. 4. It notices that B wants to migrate to A, so it tries to A to the dst list but realizes that its ->mg_preload_node is already busy. 5. and then it notices A wants to migrate to A as it's an identity migration, it culls it by list_del_init()'ing its ->mg_preload_node and putting references accordingly. 6. The rest of migration takes place with B on the src list but nothing on the dst list. This means that A isn't held while migration is in progress. If all tasks leave A before the migration finishes and the incoming task pins it, the cset will be destroyed leading to use-after-free. This is caused by overloading cset->mg_preload_node for both src and dst preload lists. We wanted to exclude the cset from the src list but ended up inadvertently excluding it from the dst list too. This patch fixes the issue by separating out cset->mg_preload_node into ->mg_src_preload_node and ->mg_dst_preload_node, so that the src and dst preloadings don't interfere with each other.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

BDU:2025-04335

Published: Feb 26, 2025
Updated: Aug 5, 2026
EPSS: 0.2% · 21th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Linux: 7.8; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

linux linux kernel3.16 and later · before 4.14.289
linux linux kernel4.15 and later · before 4.19.253
linux linux kernel4.20 and later · before 5.4.207
linux linux kernel5.5 and later · before 5.10.132
linux linux kernel5.11 and later · before 5.15.56
linux linux kernel5.16 and later · before 5.18.13
linux linux kernel5.19

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- 3.16affected
- f817de98513d060023be4fa1d061b29a6515273e and later · before 05f7658210d1d331e8dd4cb6e7bbbe3df5f5ac27affected · git
- f817de98513d060023be4fa1d061b29a6515273e and later · before cec2bbdcc14fbaa6b95ee15a7c423b05d97038beaffected · git
- f817de98513d060023be4fa1d061b29a6515273e and later · before ad44e05f3e016bdcb1ad25af35ade5b5f41ccd68affected · git
- f817de98513d060023be4fa1d061b29a6515273e and later · before 7657e3958535d101a24ab4400f9b8062b9107cc4affected · git
- f817de98513d060023be4fa1d061b29a6515273e and later · before 54aee4e5ce8c21555286a6333e46c1713880cf93affected · git
- f817de98513d060023be4fa1d061b29a6515273e and later · before 0e41774b564befa6d271e8d5086bf870d617a4e6affected · git
- f817de98513d060023be4fa1d061b29a6515273e and later · before 07fd5b6cdf3cc30bfde8fe0f644771688be04447affected · git
- before 3.16not affected · semver
- 4.14.289 and later · up to and including 4.14.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 5.18.14-1	5.18.14-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
90Now
CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
89Now
CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
85Now

Published before and after this one in the same product

← EarlierCVE-2022-49645Feb 26, 2025 · drm/panfrost: Fix shrinker list corruption by madvise IOCTL
31Monitor
← EarlierCVE-2022-49646Feb 26, 2025 · wifi: mac80211: fix queue selection for mesh/OCB interfaces
22Monitor
Later →CVE-2022-49648Feb 26, 2025 · tracing/histograms: Fix memory leak problem
22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	05f7658210d1d331e8dd4cb6e7bbbe3df5f5ac27	Vendor (CNA)
Linux Linux	07fd5b6cdf3cc30bfde8fe0f644771688be04447	Vendor (CNA)
Linux Linux	0e41774b564befa6d271e8d5086bf870d617a4e6	Vendor (CNA)
Linux Linux	54aee4e5ce8c21555286a6333e46c1713880cf93	Vendor (CNA)
Linux Linux	7657e3958535d101a24ab4400f9b8062b9107cc4	Vendor (CNA)
Linux Linux	ad44e05f3e016bdcb1ad25af35ade5b5f41ccd68	Vendor (CNA)
Linux Linux	cec2bbdcc14fbaa6b95ee15a7c423b05d97038be	Vendor (CNA)
debian:linux	5.18.14-1 · Debian:12	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Someone with local access to the system can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:11 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/05f7658210d1d331e8dd4cb6e7bbbe3df5f5ac27

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records