Kernel crash via media devnode use-after-free
Published Nov 12, 2025 · Updated May 23, 2026
Use-after-free in the Linux media controller allows local users to crash affected kernels by disconnecting a USB media device. media_devnode_unregister calls put_device, which can free the devnode, before clear_bit dereferences the freed devnode's minor number. Exploitation requires low-privileged local access and media-device teardown; the demonstrated consequence is a kernel KASAN crash.
Summary
What happened
Use-after-free in the Linux media controller allows local users to crash affected kernels by disconnecting a USB media device. media_devnode_unregister calls put_device, which can free the devnode, before clear_bit dereferences the freed devnode's minor number. Exploitation requires low-privileged local access and media-device teardown; the demonstrated consequence is a kernel KASAN crash.
The record
- CVE
- CVE-2025-40197
- Published
- Nov 12, 2025
- Updated
- May 23, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Nov 12, 2025CVE publishedPublication date reported by the CVE source.
- May 23, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <5.10.246
- Affected versionversion=0 <5.15.195
- Affected versionversion=0 <5.4.301
- Affected versionversion=0 <6.1.157
- Affected versionversion=0 <6.12.54
- Affected versionversion=0 <6.17.4
- Affected versionversion=0 <6.6.113
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5d327391f9fafeb0938be4fc538dd0bd54a0b2ef
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <64dbc6f50ce92b7da203b1bcdd96a370bbc9b74d
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7bd4e5367d0940ccec4d7546bb6bd019ab2c71aa
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7db47e737128b3585ae679b709b85f3f44cd8750
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8cfc8cec1b4da88a47c243a11f384baefd092a50
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8f52c7f38f0f2ee2afc331e6b873acba5e9490a8
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ac01416d477c2dc6016782635ae022f8cc634a29
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <dd156f44ea82cc249f46c519eed3b2f8983c8002
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- syzkaller C reproducer for media_devnode_unregister use-after-freeproof of concept · validated
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Technologies
Your stack
See the directory against your own environment.
Your stack
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