CVE-2022-49940 (GCVE-0-2022-49940)

Vulnerability from cvelistv5 – Published: 2025-06-18 10:54 – Updated: 2026-05-23 15:23
VLAI
Title
tty: n_gsm: add sanity check for gsm->receive in gsm_receive_buf()
Summary
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. 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
Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6641 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: b8faa754b523a845facdc83120b2ecd290d7fa6d , < 5a82cf64f8ad63caf6bf115642ce44ddbc64311e (git)
Affected: dfa9b6d34aac2154b5e926d7a7a061123bf137c6 , < 309aea4b6b813f6678c3a547cfd7fe3a76ffa976 (git)
Affected: 5e59c010c6862da329db17acca086afd8bea1aa8 , < 5aa37f9510345a812c0998bcbbc4d88d1dcc4d8b (git)
Affected: 01aecd917114577c423f07cec0d186ad007d76fc , < f16c6d2e58a4c2b972efcf9eb12390ee0ba3befb (git)
Affected: 2dc1be365a70699f7dda92fd9e48b84546086070 (git)
Affected: 5.18.18 , < 5.19 (semver)
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Linux Linux Affected: 5.15.61 , < 5.15.66 (semver)
Affected: 5.19.2 , < 5.19.8 (semver)
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            "lang": "es",
            "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: tty: n_gsm: a\u00f1adir comprobaci\u00f3n de validez para gsm-\u0026gt;receive en gsm_receive_buf(). Se puede producir una desreferencia de puntero nulo al intentar acceder a la funci\u00f3n \"gsm-\u0026gt;receive()\" en gsmld_receive_buf(). Actualmente, el c\u00f3digo asume que gsm-\u0026gt;recieve solo se llama despu\u00e9s de la activaci\u00f3n del MUX. Dado que se puede acceder a la funci\u00f3n gsmld_receive_buf() sin necesidad de inicializar el MUX, esta funci\u00f3n no se activar\u00e1 y se producir\u00e1 una desreferencia de puntero nulo. Para solucionar esto, se debe evitar la llamada a \"gsm-\u0026gt;receive()\" si la funci\u00f3n no se inicializa mediante una comprobaci\u00f3n de validez. Rastreo de llamadas:  gsmld_receive_buf+0x1c2/0x2f0 drivers/tty/n_gsm.c:2861 tiocsti drivers/tty/tty_io.c:2293 [en l\u00ednea] tty_ioctl+0xa75/0x15d0 drivers/tty/tty_io.c:2692 vfs_ioctl fs/ioctl.c:51 [en l\u00ednea] __do_sys_ioctl fs/ioctl.c:870 [en l\u00ednea] __se_sys_ioctl fs/ioctl.c:856 [en l\u00ednea] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [en l\u00ednea] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd"
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        "id": "CVE-2022-49940",
        "lastModified": "2026-06-17T05:19:34.990",
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                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
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                "scope": "UNCHANGED",
                "userInteraction": "NONE",
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      "current_release_date": "2026-11-11T18:39:54+00:00",
      "cve": "CVE-2022-49940",
      "id": "CVE-2022-49940",
      "initial_release_date": "2022-01-01T00:00:00+00:00",
      "product_status:fixed": "519",
      "product_status:known_not_affected": "81",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: tty: n_gsm: add sanity check for gsm-\u003ereceive in gsm_receive_buf()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2022/cve-2022-49940.json",
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}



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