net/nfc: fix use-after-free llcp_sock_bind/connect
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: net/nfc: fix use-after-free llcp_sock_bind/connect Commits 8a4cd82d ("nfc: fix refcount leak in llcp_sock_connect()") and c33b1cc62 ("nfc: fix refcount leak in llcp_sock_bind()") fixed a refcount leak bug in bind/connect but introduced a use-after-free if the same local is assigned to 2 different sockets. This can be triggered by the following simple program: int sock1 = socket( AF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP ); int sock2 = socket( AF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP ); memset( &addr, 0, sizeof(struct sockaddr_nfc_llcp) ); addr.sa_family = AF_NFC; addr.nfc_protocol = NFC_PROTO_NFC_DEP; bind( sock1, (struct sockaddr*) &addr, sizeof(struct sockaddr_nfc_llcp) ) bind( sock2, (struct sockaddr*) &addr, sizeof(struct sockaddr_nfc_llcp) ) close(sock1); close(sock2); Fix this by assigning NULL to llcp_sock->local after calling nfc_llcp_local_put. This addresses CVE-2021-23134.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 4.4.267 to before 4.4.269; 4.9.267 to before 4.9.269; 4.14.231 to before 4.14.233; 4.19.187 to before 4.19.191; 5.4.112 to before 5.4.119; 5.10.30 to before 5.10.37; 5.11.14 to before 5.11.21 | 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.119, 5.10.37, 5.11.21 | Patch available | CNA |
| Linux | Linux | 5.12 and later | 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.119, 5.10.37, 5.11.21, 5.12.4, 5.13 | Patch available | CNA |
- Linux VendorLinux Affected 4.4.267 to before 4.4.269; 4.9.267 to before 4.9.269; 4.14.231 to before 4.14.233; 4.19.187 to before 4.19.191; 5.4.112 to before 5.4.119; 5.10.30 to before 5.10.37; 5.11.14 to before 5.11.21 Fixed in 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.119, 5.10.37, 5.11.21 Patch available CNA
- Linux VendorLinux Affected 5.12 and later Fixed in 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.119, 5.10.37, 5.11.21, 5.12.4, 5.13 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.4.267 to before 4.4.269; 4.9.267 to before 4.9.269; 4.14.231 to before 4.14.233; 4.19.187 to before 4.19.191; 5.4.112 to before 5.4.119; 5.10.30 to before 5.10.37; 5.11.14 to before 5.11.21; 5.12 to before 5.12.4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.4.267 to before 4.4.269; 4.9.267 to before 4.9.269; 4.14.231 to before 4.14.233; 4.19.187 to before 4.19.191; 5.4.112 to before 5.4.119; 5.10.30 to before 5.10.37; 5.11.14 to before 5.11.21; 5.12 to before 5.12.4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.119, 5.10.37, 5.11.21
- Fix · CNA Linux (Linux) Fixed in 4.4.269, 4.9.269, 4.14.233, 4.19.191, 5.4.119, 5.10.37, 5.11.21, 5.12.4, 5.13
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
Not affected: 2 products
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-47068
- 2026-10-03 Alias added: GHSA-47q3-98v3-643r
References
Patch 9
- https://git.kernel.org/stable/c/26157c82ba756767b2bd66d28a71b1bc454447f6
- https://git.kernel.org/stable/c/ccddad6dd28530e716448e594c9ca7c76ccd0570
- https://git.kernel.org/stable/c/18ae4a192a4496e48a5490b52812645d2413307c
- https://git.kernel.org/stable/c/48fba458fe54cc2a980a05c13e6c19b8b2cfb610
- https://git.kernel.org/stable/c/e32352070bcac22be6ed8ab635debc280bb65b8c
- https://git.kernel.org/stable/c/6b7021ed36dabf29e56842e3408781cd3b82ef6e
- https://git.kernel.org/stable/c/374cdde4dcc9c909a60713abdbbf96d5e3e09f91
- https://git.kernel.org/stable/c/18175fe17ae043a0b81e5d511f8817825784c299
- https://git.kernel.org/stable/c/c61760e6940dd4039a7f5e84a6afc9cdbf4d82b6
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2021-47068 · CVE Program
- CVE-2021-47068 · NVD
- FIRST EPSS
- GHSA-47q3-98v3-643r · GitHub Advisory Database · CC BY 4.0
- CVE-2021-47068 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences