ghsa-r633-2867-crc8
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
net: hso: fix null-ptr-deref during tty device unregistration
Multiple ttys try to claim the same the minor number causing a double unregistration of the same device. The first unregistration succeeds but the next one results in a null-ptr-deref.
The get_free_serial_index() function returns an available minor number but doesn't assign it immediately. The assignment is done by the caller later. But before this assignment, calls to get_free_serial_index() would return the same minor number.
Fix this by modifying get_free_serial_index to assign the minor number immediately after one is found to be and rename it to obtain_minor() to better reflect what it does. Similary, rename set_serial_by_index() to release_minor() and modify it to free up the minor number of the given hso_serial. Every obtain_minor() should have corresponding release_minor() call.
{
"affected": [],
"aliases": [
"CVE-2021-46904"
],
"database_specific": {
"cwe_ids": [
"CWE-476"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-02-26T16:27:45Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: hso: fix null-ptr-deref during tty device unregistration\n\nMultiple ttys try to claim the same the minor number causing a double\nunregistration of the same device. The first unregistration succeeds\nbut the next one results in a null-ptr-deref.\n\nThe get_free_serial_index() function returns an available minor number\nbut doesn\u0027t assign it immediately. The assignment is done by the caller\nlater. But before this assignment, calls to get_free_serial_index()\nwould return the same minor number.\n\nFix this by modifying get_free_serial_index to assign the minor number\nimmediately after one is found to be and rename it to obtain_minor()\nto better reflect what it does. Similary, rename set_serial_by_index()\nto release_minor() and modify it to free up the minor number of the\ngiven hso_serial. Every obtain_minor() should have corresponding\nrelease_minor() call.",
"id": "GHSA-r633-2867-crc8",
"modified": "2024-04-17T21:30:45Z",
"published": "2024-02-26T18:30:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-46904"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/145c89c441d27696961752bf51b323f347601bee"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/388d05f70f1ee0cac4a2068fd295072f1a44152a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4a2933c88399c0ebc738db39bbce3ae89786d723"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8a12f8836145ffe37e9c8733dce18c22fb668b66"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/92028d7a31e55d53e41cff679156b9432cffcb36"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a462067d7c8e6953a733bf5ade8db947b1bb5449"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/caf5ac93b3b5d5fac032fc11fbea680e115421b4"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dc195928d7e4ec7b5cfc6cd10dc4c8d87a7c72ac"
}
],
"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"
}
]
}