CVE-2026-64010

In the Linux kernel, the following vulnerability has been resolved:

nfc: llcp: Fix use-after-free race in nfc_llcp_recv_cc()

A race condition exists in the NFC LLCP connection state machine where the connection acceptance packet (CC) can be processed concurrently with socket release. This can lead to a use-after-free of the socket object.

When nfc_llcp_recv_cc() moves the socket from the connecting_sockets list to the sockets list, it does so without holding the socket lock. If llcp_sock_release() is executing concurrently, it might have already unlinked the socket and dropped its references, which can result in nfc_llcp_recv_cc() linking a freed socket into the live list.

Fix this by holding lock_sock() during the state transition and list movement in nfc_llcp_recv_cc(). After acquiring the lock, check if the socket is still hashed to ensure it hasnt already been unlinked and marked for destruction by the release path. This aligns the locking pattern with recv_hdlc() and recv_disc().

Weakness

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Affected Software

Extended Description

A race condition occurs within concurrent environments, and it is effectively a property of a code sequence. Depending on the context, a code sequence may be in the form of a function call, a small number of instructions, a series of program invocations, etc. A race condition violates these properties, which are closely related:

A race condition exists when an “interfering code sequence” can still access the shared resource, violating exclusivity. The interfering code sequence could be “trusted” or “untrusted.” A trusted interfering code sequence occurs within the product; it cannot be modified by the attacker, and it can only be invoked indirectly. An untrusted interfering code sequence can be authored directly by the attacker, and typically it is external to the vulnerable product.

Potential Mitigations

• Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring.
• Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/29.html

References

• https://git.kernel.org/stable/c/0b45c31746e1523d5d482fda8fcf54a35ac417f1
• https://git.kernel.org/stable/c/650bdd8fdfab64a09ee474150313dbc48c374795
• https://git.kernel.org/stable/c/ad8a27d63cac96bac441edd002209ebd996e12fb
• https://git.kernel.org/stable/c/b2a60f7f846faaf5c2cdad4ea6d3a33e5f863183
• https://git.kernel.org/stable/c/b493ea2765cc17cb8aa7e7544a4b6dcb05b6ed77
• https://git.kernel.org/stable/c/bd08bb7443c501d2f2a71d529e4afcf11c9b07d2
• https://git.kernel.org/stable/c/dce85215a6c7b0fd753f577a4c487f647119884c
• https://git.kernel.org/stable/c/ee2d1a8a1833c5e56e9a1745e64b0b4edda732c2