Local kernel corruption via shared NFC local object
Published Feb 29, 2024 · Updated Aug 5, 2026
Use-after-free in affected Linux kernel NFC LLCP builds allows local users to corrupt kernel memory through crafted socket operations. The llcp_sock_bind and llcp_sock_connect paths can assign one nfc_llcp_local object to two sockets; closing the first drops the shared reference while the second socket retains the freed pointer. A local low-privileged process must create and bind or connect multiple AF_NFC LLCP sockets to the same local object, after which socket teardown can crash the kernel or compromise kernel execution.
Summary
What happened
Use-after-free in affected Linux kernel NFC LLCP builds allows local users to corrupt kernel memory through crafted socket operations. The llcp_sock_bind and llcp_sock_connect paths can assign one nfc_llcp_local object to two sockets; closing the first drops the shared reference while the second socket retains the freed pointer. A local low-privileged process must create and bind or connect multiple AF_NFC LLCP sockets to the same local object, after which socket teardown can crash the kernel or compromise kernel execution.
The record
- CVE
- CVE-2021-47068
- Published
- Feb 29, 2024
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-416
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 29, 2024CVE publishedPublication date reported by the CVE source.
- Aug 5, 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=18013007b596771bf5f5e7feee9586fb0386ad14 <ccddad6dd28530e716448e594c9ca7c76ccd0570
- Affected versionversion=4.14.231 <4.14.233
- Affected versionversion=4.19.187 <4.19.191
- Affected versionversion=4.4.267 <4.4.269
- Affected versionversion=4.9.267 <4.9.269
- Affected versionversion=5.10.30 <5.10.37
- Affected versionversion=5.11.14 <5.11.21
- Affected versionversion=5.12
- Affected versionversion=538a6ff11516d38a61e237d2d2dc04c30c845fbe <18ae4a192a4496e48a5490b52812645d2413307c
- Affected versionversion=5.4.112 <5.4.119
- Affected versionversion=6fb003e5ae18d8cda4c8a1175d9dd8db12bec049 <6b7021ed36dabf29e56842e3408781cd3b82ef6e
- Affected versionversion=8c9e4971e142e2899606a2490b77a1208c1f4638 <374cdde4dcc9c909a60713abdbbf96d5e3e09f91
- Affected versionversion=a1cdd18c49d23ec38097ac2c5b0d761146fc0109 <26157c82ba756767b2bd66d28a71b1bc454447f6
- Affected versionversion=adbb1d218c5f56dbae052765da83c0f57fce2a31 <48fba458fe54cc2a980a05c13e6c19b8b2cfb610
- Affected versionversion=c33b1cc62ac05c1dbb1cdafe2eb66da01c76ca8d <18175fe17ae043a0b81e5d511f8817825784c299
- Affected versionversion=c33b1cc62ac05c1dbb1cdafe2eb66da01c76ca8d <c61760e6940dd4039a7f5e84a6afc9cdbf4d82b6
- Affected versionversion=c89903c9eff219a4695e63715cf922748d743f65 <e32352070bcac22be6ed8ab635debc280bb65b8c
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
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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