CVE-2021-46904

Advisory lineage Upstream: 0 Downstream: 11
Modified
Published: 25 Feb 2024, 14:03
Last modified:11 May 2026, 13:44

Vulnerability Summary

Overall Risk (default)
low
22/100
CVSS Score
5.5 MEDIUM
v3.1 (nvd)
EPSS Score
0.01% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

25 Feb 2024, 14:03
Published
Vulnerability first disclosed
11 May 2026, 13:44
Last Modified
Vulnerability information updated

Description

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.

CVSS Metrics

  • v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.01%• Percentile: 2%

Techniques & Countermeasures

  • CWE-476•NULL Pointer Dereference

    The product dereferences a pointer that it expects to be valid but is NULL.

Affected Systems

  • linux•linux

    ≥ 72dc1c096c7051a48ab1dbb12f71976656b55eb5, < a462067d7c8e6953a733bf5ade8db947b1bb5449 | ≥ 72dc1c096c7051a48ab1dbb12f71976656b55eb5, < 145c89c441d27696961752bf51b323f347601bee | ≥ 72dc1c096c7051a48ab1dbb12f71976656b55eb5, < caf5ac93b3b5d5fac032fc11fbea680e115421b4 | ≥ 72dc1c096c7051a48ab1dbb12f71976656b55eb5, < 92028d7a31e55d53e41cff679156b9432cffcb36 | ≥ 72dc1c096c7051a48ab1dbb12f71976656b55eb5, < 4a2933c88399c0ebc738db39bbce3ae89786d723 | ≥ 72dc1c096c7051a48ab1dbb12f71976656b55eb5, < dc195928d7e4ec7b5cfc6cd10dc4c8d87a7c72ac | ≥ 72dc1c096c7051a48ab1dbb12f71976656b55eb5, < 388d05f70f1ee0cac4a2068fd295072f1a44152a | ≥ 72dc1c096c7051a48ab1dbb12f71976656b55eb5, < 8a12f8836145ffe37e9c8733dce18c22fb668b66 | 2.6.27

  • linux•linux_kernel

    ≥ 2.6.27, < 4.4.268 | ≥ 4.5.0, < 4.9.268 | ≥ 4.10.0, < 4.14.232 | ≥ 4.15.0, < 4.19.187 | ≥ 4.20.0, < 5.4.112 | ≥ 5.5.0, < 5.10.30 | ≥ 5.11.0, < 5.11.14

References (8)