NVD / CVE Program· CNA Linux

CVE-2023-52854: padata: Fix refcnt handling in padata_free_shell()

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: 0.24% (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 0dd34a7ad395dbcf6ae60e48e9786050e25b9bc5, 1734a79e951914f1db2c65e635012a35db1c674b, 1e901bcb8af19416b65f5063a4af7996e5a51d7f.

Low priority for now. Upgrade to Linux Linux 0dd34a7ad395dbcf6ae60e48e9786050e25b9bc5, 1734a79e951914f1db2c65e635012a35db1c674b, 1e901bcb8af19416b65f5063a4af7996e5a51d7f 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: padata: Fix refcnt handling in padata_free_shell() In a high-load arm64 environment, the pcrypt_aead01 test in LTP can lead to system UAF (Use-After-Free) issues. Due to the lengthy analysis of the pcrypt_aead01 function call, I'll describe the problem scenario using a simplified model: Suppose there's a user of padata named `user_function` that adheres to the padata requirement of calling `padata_free_shell` after `serial()` has been invoked, as demonstrated in the following code: ```c struct request { struct padata_priv padata; struct completion *done; }; void parallel(struct padata_priv *padata) { do_something(); } void serial(struct padata_priv *padata) { struct request *request = container_of(padata, struct request, padata); complete(request->done); } void user_function() { DECLARE_COMPLETION(done) padata->parallel = parallel; padata->serial = serial; padata_do_parallel(); wait_for_completion(&done); padata_free_shell(); } ``` In the corresponding padata.c file, there's the following code: ```c static void padata_serial_worker(struct work_struct *serial_work) { ... cnt = 0; while (!list_empty(&local_list)) { ... padata->serial(padata); cnt++; } local_bh_enable(); if (refcount_sub_and_test(cnt, &pd->refcnt)) padata_free_pd(pd); } ``` Because of the high system load and the accumulation of unexecuted softirq at this moment, `local_bh_enable()` in padata takes longer to execute than usual. Subsequently, when accessing `pd->refcnt`, `pd` has already been released by `padata_free_shell()`, resulting in a UAF issue with `pd->refcnt`. The fix is straightforward: add `refcount_dec_and_test` before calling `padata_free_pd` in `padata_free_shell`.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

Published: May 21, 2024
Updated: Jun 17, 2026
EPSS: 0.2% · 15th 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: partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

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?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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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.

ProductVersion

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 kernel3.16.84 and later · before 3.17
linux linux kernel4.4.215 and later · before 4.5
linux linux kernel4.9.215 and later · before 4.10
linux linux kernel4.14.172 and later · before 4.15
linux linux kernel4.19.103 and later · before 4.20
linux linux kernel5.4.19 and later · before 5.5
linux linux kernel5.5.3 and later · before 5.10.201
linux linux kernel5.11 and later · before 5.15.139
linux linux kernel5.16 and later · before 6.1.63
linux linux kernel6.2 and later · before 6.5.12
linux linux kernel6.6 and later · before 6.6.2

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
- 13721e447acc2b82c19cf72e9e6c4291c77693ed, 7a2ccb65f90168edc2348495bb56093c466ffa39, 928cf3d733c4efc221e1a78b14cb2ee066627260, c9da8ee1491719001a444f4af688b75e72b58418, dc34710a7aba5207e7cb99d11588c04535b3c53d, 5fefc9b3e3584a1ce98da27c38e1b8dda1939d74, 26daf8e6515c2dcd25d235468420b9f46e0acdac, 5.6affected
- 07928d9bfc81640bab36f5190e8725894d93b659 and later · before 41aad9d6953984d134fc50f631f24ef476875d4daffected · git
- 07928d9bfc81640bab36f5190e8725894d93b659 and later · before 0dd34a7ad395dbcf6ae60e48e9786050e25b9bc5affected · git
- 07928d9bfc81640bab36f5190e8725894d93b659 and later · before c7c26d0ef5d20f00dbb2ae3befcabbe0efa77275affected · git
- 07928d9bfc81640bab36f5190e8725894d93b659 and later · before 1e901bcb8af19416b65f5063a4af7996e5a51d7faffected · git
- 07928d9bfc81640bab36f5190e8725894d93b659 and later · before 1734a79e951914f1db2c65e635012a35db1c674baffected · git
- 07928d9bfc81640bab36f5190e8725894d93b659 and later · before 7ddc21e317b360c3444de3023bcc83b85fabae2faffected · git
- 3.16.84 and later · before 3.17affected · semver
- 4.4.215 and later · before 4.5affected · semver
- 4.9.215 and later · before 4.10affected · 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 6.1.64-1	6.1.64-1
Debian:13	linux	before 6.6.8-1	6.6.8-1
SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS	kernel-default-base	before 5.3.18-150200.24.203.1.150200.9.105.1	5.3.18-150200.24.203.1.150200.9.105.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS	kernel-docs	before 5.3.18-150200.24.203.1	5.3.18-150200.24.203.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS	kernel-obs-build	before 5.3.18-150200.24.203.1	5.3.18-150200.24.203.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS	kernel-preempt	before 5.3.18-150200.24.203.1	5.3.18-150200.24.203.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS	kernel-source	before 5.3.18-150200.24.203.1	5.3.18-150200.24.203.1
SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS	kernel-syms	before 5.3.18-150200.24.203.1	5.3.18-150200.24.203.1
SUSE:Linux Enterprise Live Patching 15 SP2	kernel-default	before 5.3.18-150200.24.203.1	5.3.18-150200.24.203.1
SUSE:Linux Enterprise Live Patching 15 SP2	kernel-livepatch-SLE15-SP2_Update_52	before 1-150200.5.3.1	1-150200.5.3.1

Same product

linux: all records

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Published before and after this one in the same product

← EarlierCVE-2023-52852May 21, 2024 · f2fs: compress: fix to avoid use-after-free on dic
31Monitor
← EarlierCVE-2023-52853May 21, 2024 · hid: cp2112: Fix duplicate workqueue initialization
22Monitor
Later →CVE-2023-52855May 21, 2024 · usb: dwc2: fix possible NULL pointer dereference caused by driver concurrency
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	0dd34a7ad395dbcf6ae60e48e9786050e25b9bc5	Vendor (CNA)
Linux Linux	1734a79e951914f1db2c65e635012a35db1c674b	Vendor (CNA)
Linux Linux	1e901bcb8af19416b65f5063a4af7996e5a51d7f	Vendor (CNA)
Linux Linux	3.17	Vendor (CNA)
Linux Linux	4.10	Vendor (CNA)
Linux Linux	4.15	Vendor (CNA)
Linux Linux	4.20	Vendor (CNA)
Linux Linux	4.5	Vendor (CNA)
Linux Linux	41aad9d6953984d134fc50f631f24ef476875d4d	Vendor (CNA)
Linux Linux	5.5	Vendor (CNA)
Linux Linux	5.6	Vendor (CNA)
Linux Linux	7ddc21e317b360c3444de3023bcc83b85fabae2f	Vendor (CNA)
Linux Linux	c7c26d0ef5d20f00dbb2ae3befcabbe0efa77275	Vendor (CNA)
debian:linux	6.1.64-1 · Debian:12	Package registry (OSV)
suse:kernel-default	5.3.18-150200.24.203.1 · SUSE:Linux Enterprise Live Patching 15 SP2	Package registry (OSV)
suse:kernel-default-base	5.3.18-150200.24.203.1.150200.9.105.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS	Package registry (OSV)
suse:kernel-docs	5.3.18-150200.24.203.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS	Package registry (OSV)
suse:kernel-livepatch-SLE15-SP2_Update_52	1-150200.5.3.1 · SUSE:Linux Enterprise Live Patching 15 SP2	Package registry (OSV)
suse:kernel-obs-build	5.3.18-150200.24.203.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS	Package registry (OSV)
suse:kernel-preempt	5.3.18-150200.24.203.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS	Package registry (OSV)
suse:kernel-source	5.3.18-150200.24.203.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS	Package registry (OSV)
suse:kernel-syms	5.3.18-150200.24.203.1 · SUSE:Linux Enterprise High Performance Computing 15 SP2-LTSS	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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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-primary

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/0dd34a7ad395dbcf6ae60e48e9786050e25b9bc5

Show all references (5 more)

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

All records