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GHSA-52J6-G7FJ-MFJM

Vulnerability from github – Published: 2025-06-18 12:30 – Updated: 2025-11-14 21:30

Details

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: 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

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{
  "affected": [],
  "aliases": [
    "CVE-2022-49940"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-476"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-06-18T11:15:20Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntty: n_gsm: add sanity check for gsm-\u003ereceive in gsm_receive_buf()\n\nA null pointer dereference can happen when attempting to access the\n\"gsm-\u003ereceive()\" function in gsmld_receive_buf(). Currently, the code\nassumes that gsm-\u003erecieve is only called after MUX activation.\nSince the gsmld_receive_buf() function can be accessed without the need to\ninitialize the MUX, the gsm-\u003ereceive() function will not be set and a\nNULL pointer dereference will occur.\n\nFix this by avoiding the call to \"gsm-\u003ereceive()\" in case the function is\nnot initialized by adding a sanity check.\n\nCall Trace:\n \u003cTASK\u003e\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",
  "id": "GHSA-52j6-g7fj-mfjm",
  "modified": "2025-11-14T21:30:27Z",
  "published": "2025-06-18T12:30:35Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49940"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/309aea4b6b813f6678c3a547cfd7fe3a76ffa976"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5a82cf64f8ad63caf6bf115642ce44ddbc64311e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5aa37f9510345a812c0998bcbbc4d88d1dcc4d8b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f16c6d2e58a4c2b972efcf9eb12390ee0ba3befb"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

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

Vulnerability from cvelistv5 – Published: 2025-06-18 10:54 – Updated: 2026-05-23 15:23

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

No CVSS data available.

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/5a82cf64f8ad63caf…
https://git.kernel.org/stable/c/309aea4b6b813f667…
https://git.kernel.org/stable/c/5aa37f9510345a812…
https://git.kernel.org/stable/c/f16c6d2e58a4c2b97…

Impacted products

2 products

Vendor	Product	Version
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)
Linux	Linux	Affected: 5.15.61 , < 5.15.66 (semver) Affected: 5.19.2 , < 5.19.8 (semver)

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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