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CVE-2022-49940

Estado: AnalizadaMedia (5.5)—

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

tty: n_gsm: add sanity check for gsm->receive in gsm_receive_buf()

A null pointer dereference can happen when attempting to access the "gsm->receive()" function in gsmld_receive_buf(). Currently, the code assumes that gsm->recieve is only called after MUX activation. Since the gsmld_receive_buf() function can be accessed without the need to initialize the MUX, the gsm->receive() function will not be set and a NULL pointer dereference will occur.

Fix this by avoiding the call to "gsm->receive()" in case the function is not initialized by adding a sanity check.

Detalles técnicos trazas, registros y código del informe original
Call Trace:
 <TASK>
 gsmld_receive_buf+0x1c2/0x2f0 drivers/tty/n_gsm.c:2861
 tiocsti drivers/tty/tty_io.c:2293 [inline]
 tty_ioctl+0xa75/0x15d0 drivers/tty/tty_io.c:2692
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2022-49940",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.5,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 1.8
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          "programFiles": [
            "drivers/tty/n_gsm.c"
          ],
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2025-06-18T11:15:20.917",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/309aea4b6b813f6678c3a547cfd7fe3a76ffa976",
      "tags": [
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      "tags": [
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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  "vulnStatus": "Analyzed",
  "weaknesses": [
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      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntty: n_gsm: add sanity check for gsm->receive in gsm_receive_buf()\n\nA null pointer dereference can happen when attempting to access the\n\"gsm->receive()\" function in gsmld_receive_buf(). Currently, the code\nassumes that gsm->recieve is only called after MUX activation.\nSince the gsmld_receive_buf() function can be accessed without the need to\ninitialize the MUX, the gsm->receive() function will not be set and a\nNULL pointer dereference will occur.\n\nFix this by avoiding the call to \"gsm->receive()\" in case the function is\nnot initialized by adding a sanity check.\n\nCall Trace:\n <TASK>\n gsmld_receive_buf+0x1c2/0x2f0 drivers/tty/n_gsm.c:2861\n tiocsti drivers/tty/tty_io.c:2293 [inline]\n tty_ioctl+0xa75/0x15d0 drivers/tty/tty_io.c:2692\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:870 [inline]\n __se_sys_ioctl fs/ioctl.c:856 [inline]\n __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x63/0xcd"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: tty: n_gsm: añadir comprobación de validez para gsm-&gt;receive en gsm_receive_buf(). Se puede producir una desreferencia de puntero nulo al intentar acceder a la función \"gsm-&gt;receive()\" en gsmld_receive_buf(). Actualmente, el código asume que gsm-&gt;recieve solo se llama después de la activación del MUX. Dado que se puede acceder a la función gsmld_receive_buf() sin necesidad de inicializar el MUX, esta función no se activará y se producirá una desreferencia de puntero nulo. Para solucionar esto, se debe evitar la llamada a \"gsm-&gt;receive()\" si la función no se inicializa mediante una comprobación de validez. Rastreo de llamadas:  gsmld_receive_buf+0x1c2/0x2f0 drivers/tty/n_gsm.c:2861 tiocsti drivers/tty/tty_io.c:2293 [en línea] tty_ioctl+0xa75/0x15d0 drivers/tty/tty_io.c:2692 vfs_ioctl fs/ioctl.c:51 [en línea] __do_sys_ioctl fs/ioctl.c:870 [en línea] __se_sys_ioctl fs/ioctl.c:856 [en línea] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [en línea] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd"
    }
  ],
  "lastModified": "2026-06-17T05:19:34.990",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
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}