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CVE-2026-64011
nfc: llcp: Fix use-after-free in llcp_sock_release()
Published 2026-07-19 (3 months ago) by the Linux kernel CNA. Subsystem net/nfc. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-64011 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | fixed | 6.1.176-1 | Update the kernel and reboot. Fixed in 6.1.176-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.94-1 | Update the kernel and reboot. Fixed in 6.12.94-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.0.12-1 | Update the kernel and reboot. Fixed in 7.0.12-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.0.12-1 | Update the kernel and reboot. Fixed in 7.0.12-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
llcp_sock_release() unconditionally unlinks the socket from the local sockets list. However, if the socket is still in connecting state, it is on the connecting list. Fix this by checking the socket state and unlinking from the correct list.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
net/nfc/llcp_sock.c
- What this is
- NFC SUBSYSTEMMAINTAINERS section matched on net/nfc/ · oe-linux-nfc@lists.linux.dev · Maintained
- Kernel module
- nfc
Check it on the machine
grep -w CONFIG_NFC /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w nfcPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookworm, trixie, forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64
- M
- a module where it is built at all; some flavours do not build it
- Build switch
- CONFIG_NFC
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-07-19 (3 months ago)source
- CVSS
- 7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.13%, higher than 2.0% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- net/nfc
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 3.11 | 5.10.259 | 89ba02674701 |
| 3.11 | 5.15.210 | fb29f6bbe433 |
| 3.11 | 6.1.176 | 2dfdaaf7d933 |
| 3.11 | 6.6.143 | e00f50f86977 |
| 3.11 | 6.12.93 | cdc17e09a636 |
| 3.11 | 6.18.35 | 912ebc49d440 |
| 3.11 | 7.0.12 | bc421d0826de |
| 3.11 | 7.1 | f4268b466190 |
| 3.10.10 | 0 | 0 |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- The bug is triggered in llcp_sock_release() via the local close(2) syscall on an AF_NFC LLCP socket left in LLCP_CONNECTING after a non-blocking connect(); no remote network protocol reaches this unlink path directly.
- AC:LAttack complexity, low
- An attacker fully controls the race by opening an LLCP socket, calling connect() with O_NONBLOCK, and immediately closing it; no privileged setup or uncontrollable memory-layout conditions are required beyond an active NFC DEP link.
- PR:LPrivileges required, low
- SOCK_STREAM/SOCK_DGRAM LLCP sockets require no capability checks at creation or release (only SOCK_RAW needs CAP_NET_RAW), so any unprivileged local process in init_net can reach the vulnerable close() path once an NFC DEP session is up.
- UI:NUser interaction, none
- Exploitation requires only programmatic socket connect/close calls from a malicious local process; no victim user action (such as tapping, mounting, or opening a file) is needed at exploit time if an NFC link is already established.
- S:UScope, unchanged
- The use-after-free corrupts kernel heap memory within the same kernel security boundary and can lead to local privilege escalation, not a cross-boundary escape such as VM or sandbox breakout.
- C:HConfidentiality impact, high
- This is a kernel heap use-after-free of struct nfc_llcp_sock; freed socket objects can be reallocated and read through subsequent list lookups or concurrent recv_cc()/recv_dm() processing, enabling arbitrary kernel memory disclosure.
- I:HIntegrity impact, high
- A use-after-free on a socket structure embedded in struct sock provides standard kernel heap-spray primitives that can be leveraged for arbitrary write and local privilege escalation via control-flow hijacking.
- A:HAvailability impact, high
- The use-after-free can cause immediate kernel oops/panic during concurrent list traversal or socket teardown, and successful exploitation yields full kernel compromise with total system unavailability.