CVE-2023-52919 in Linux
Summary
by MITRE • 10/22/2024
In the Linux kernel, the following vulnerability has been resolved:
nfc: nci: fix possible NULL pointer dereference in send_acknowledge()
Handle memory allocation failure from nci_skb_alloc() (calling alloc_skb()) to avoid possible NULL pointer dereference.
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Analysis
by VulDB Data Team • 01/19/2026
The vulnerability identified as CVE-2023-52919 represents a critical NULL pointer dereference issue within the Linux kernel's NFC (Near Field Communication) subsystem, specifically affecting the NCI (NFC Controller Interface) layer. This flaw exists in the send_acknowledge() function where the kernel fails to properly handle memory allocation failures during NFC command processing. The vulnerability stems from the nci_skb_alloc() function which internally calls alloc_skb() to allocate socket buffers for NFC communication packets. When memory allocation fails, nci_skb_alloc() returns a NULL pointer, but the send_acknowledge() function does not validate this return value before attempting to dereference the pointer, creating a potential crash condition.
The technical implementation of this vulnerability occurs within the NFC controller interface driver where the kernel attempts to construct and send acknowledgment packets in response to NFC commands received from external devices. When the system experiences memory pressure or allocation limits are reached, the alloc_skb() function returns NULL instead of a valid socket buffer structure. The send_acknowledge() function proceeds without checking for this NULL return value, leading to an immediate NULL pointer dereference when the code attempts to access members of the invalid pointer. This condition results in a kernel oops or system crash, effectively causing a denial of service condition that can be exploited by malicious actors to disrupt NFC functionality or potentially escalate privileges through controlled memory allocation failure conditions.
From an operational impact perspective, this vulnerability affects systems running Linux kernels with NFC support, particularly those implementing NFC controllers that utilize the NCI protocol interface. The flaw can be triggered through normal NFC operations when the system encounters memory allocation failures during NFC command processing, potentially allowing attackers to cause system instability or denial of service conditions. The vulnerability aligns with CWE-476 which describes NULL pointer dereference conditions, and could be categorized under ATT&CK technique T1499.004 for network denial of service. Systems utilizing NFC for payment processing, device pairing, or secure communication protocols are particularly at risk as the denial of service could disrupt critical NFC-based services.
Mitigation strategies for CVE-2023-52919 focus on implementing proper error handling within the kernel code to validate memory allocation results before proceeding with pointer operations. The fix involves adding a NULL check immediately after the nci_skb_alloc() call within the send_acknowledge() function to ensure that memory allocation failures are properly handled. System administrators should prioritize applying the kernel patches that address this vulnerability, which typically involve updating to kernel versions that include the memory allocation validation fix. Additionally, monitoring systems for memory pressure conditions and implementing proper resource management can help reduce the likelihood of triggering this vulnerability. Organizations should also consider implementing intrusion detection systems that can monitor for unusual NFC-related kernel crashes or memory allocation failures that might indicate exploitation attempts. The fix demonstrates proper defensive programming practices that align with secure coding guidelines and kernel security best practices for handling allocation failures in kernel space operations.