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NVD / CVE Program· CNA Linux

CVE-2025-37747: perf: Fix hang while freeing sigtrap event

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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 1267bd38f161c1a27d9b722de017027167a225a0, 5.16, 56799bc035658738f362acec3e7647bb84e68933; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes.

Low priority for now. Upgrade to Linux Linux 1267bd38f161c1a27d9b722de017027167a225a0, 5.16, 56799bc035658738f362acec3e7647bb84e68933; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes 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: perf: Fix hang while freeing sigtrap event Perf can hang while freeing a sigtrap event if a related deferred signal hadn't managed to be sent before the file got closed: perf_event_overflow() task_work_add(perf_pending_task) fput() task_work_add(____fput()) task_work_run() ____fput() perf_release() perf_event_release_kernel() _free_event() perf_pending_task_sync() task_work_cancel() -> FAILED rcuwait_wait_event() Once task_work_run() is running, the list of pending callbacks is removed from the task_struct and from this point on task_work_cancel() can't remove any pending and not yet started work items, hence the task_work_cancel() failure and the hang on rcuwait_wait_event(). Task work could be changed to remove one work at a time, so a work running on the current task can always cancel a pending one, however the wait / wake design is still subject to inverted dependencies when remote targets are involved, as pictured by Oleg: T1 T2 fd = perf_event_open(pid => T2->pid); fd = perf_event_open(pid => T1->pid); close(fd) close(fd) <IRQ> <IRQ> perf_event_overflow() perf_event_overflow() task_work_add(perf_pending_task) task_work_add(perf_pending_task) </IRQ> </IRQ> fput() fput() task_work_add(____fput()) task_work_add(____fput()) task_work_run() task_work_run() ____fput() ____fput() perf_release() perf_release() perf_event_release_kernel() perf_event_release_kernel() _free_event() _free_event() perf_pending_task_sync() perf_pending_task_sync() rcuwait_wait_event() rcuwait_wait_event() Therefore the only option left is to acquire the event reference count upon queueing the perf task work and release it from the task work, just like it was done before 3a5465418f5f ("perf: Fix event leak upon exec and file release") but without the leaks it fixed. Some adjustments are necessary to make it work: * A child event might dereference its parent upon freeing. Care must be taken to release the parent last. * Some places assuming the event doesn't have any reference held and therefore can be freed right away must instead put the reference and let the reference counting to its job.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 1, 2025
Updated
Oct 21, 2026
EPSS
0.2% · 16th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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  • 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.

VendorProduct
linuxlinux kernel

Affected versions

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

  • linux linux kernel5.15.165 and later · before 5.16
  • linux linux kernel6.1.103 and later · before 6.2
  • linux linux kernel6.6.44 and later · before 6.7
  • linux linux kernel6.10.3 and later · before 6.12.24
  • linux linux kernel6.13 and later · before 6.13.12
  • linux linux kernel6.14 and later · before 6.14.3
  • linux linux kernel6.15

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

    • 9ad46f1fef421d43cdab3a7d1744b2f43b54dae0, ed2c202dac55423a52d7e2290f2888bf08b8ee99, f34d8307a73a18de5320fcc6f40403146d061891, 6.11affected
    • 104e258a004037bc7dba9f6085c71dad6af57ad4 and later · before aae58a39ac4c63c3fa53536fb2504c9f1d0e1719affected · git
    • 3a5465418f5fd970e86a86c7f4075be262682840 and later · before fa1827fa968c0674e9b6fca223fa9fb4da4493ebaffected · git
    • 3a5465418f5fd970e86a86c7f4075be262682840 and later · before 665b87b8f8b3aeb49083ef3b65c4953e7753fc12affected · git
    • 3a5465418f5fd970e86a86c7f4075be262682840 and later · before 1267bd38f161c1a27d9b722de017027167a225a0affected · git
    • 3a5465418f5fd970e86a86c7f4075be262682840 and later · before 56799bc035658738f362acec3e7647bb84e68933affected · git
    • 6.6.44 and later · before 6.6.160affected · semver
    • 5.15.165 and later · before 5.16affected · semver
    • 6.1.103 and later · before 6.2affected · semver
    • 6.10.3 and later · before 6.11affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:13linuxbefore 6.12.25-16.12.25-1

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-2025-37743May 1, 2025 · wifi: ath12k: Avoid memory leak while enabling statistics
    22Monitor
  • ← EarlierCVE-2025-37746May 1, 2025 · perf/dwc_pcie: fix duplicate pci_dev devices
    22Monitor
  • Later →CVE-2025-37750May 1, 2025 · smb: client: fix UAF in decryption with multichannel
    31Monitor

Remediation

Which version to upgrade to

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

Product / packageFixed versionSource
Linux Linux1267bd38f161c1a27d9b722de017027167a225a0Vendor (CNA)
Linux Linux5.16Vendor (CNA)
Linux Linux56799bc035658738f362acec3e7647bb84e68933Vendor (CNA)
Linux Linux6.11Vendor (CNA)
Linux Linux6.2Vendor (CNA)
Linux Linux6.6.160Vendor (CNA)
Linux Linux665b87b8f8b3aeb49083ef3b65c4953e7753fc12Vendor (CNA)
Linux Linuxaae58a39ac4c63c3fa53536fb2504c9f1d0e1719Vendor (CNA)
Linux Linuxfa1827fa968c0674e9b6fca223fa9fb4da4493ebVendor (CNA)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0Release NotesMicrosoft (MSRC)
debian:linux6.12.25-1 · Debian:13Package 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
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-primary

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

  1. Fix✗ → ✓

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

References

Show all references (4 more)

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

All records