Vulnerability 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 Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 2.6.27, < 4.4.268 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/145c89c441d27696961752bf51b323f347601beePatch
- https://git.kernel.org/stable/c/388d05f70f1ee0cac4a2068fd295072f1a44152aPatch
- https://git.kernel.org/stable/c/4a2933c88399c0ebc738db39bbce3ae89786d723Patch
- https://git.kernel.org/stable/c/8a12f8836145ffe37e9c8733dce18c22fb668b66Patch
- https://git.kernel.org/stable/c/92028d7a31e55d53e41cff679156b9432cffcb36Patch
- https://git.kernel.org/stable/c/a462067d7c8e6953a733bf5ade8db947b1bb5449Patch
- https://git.kernel.org/stable/c/caf5ac93b3b5d5fac032fc11fbea680e115421b4Patch
- https://git.kernel.org/stable/c/dc195928d7e4ec7b5cfc6cd10dc4c8d87a7c72acPatch
- https://git.kernel.org/stable/c/145c89c441d27696961752bf51b323f347601beePatch
- https://git.kernel.org/stable/c/388d05f70f1ee0cac4a2068fd295072f1a44152aPatch
- https://git.kernel.org/stable/c/4a2933c88399c0ebc738db39bbce3ae89786d723Patch
- https://git.kernel.org/stable/c/8a12f8836145ffe37e9c8733dce18c22fb668b66Patch
- https://git.kernel.org/stable/c/92028d7a31e55d53e41cff679156b9432cffcb36Patch
- https://git.kernel.org/stable/c/a462067d7c8e6953a733bf5ade8db947b1bb5449Patch
- https://git.kernel.org/stable/c/caf5ac93b3b5d5fac032fc11fbea680e115421b4Patch
FAQ
What is CVE-2021-46904?
CVE-2021-46904 is a vulnerability with a CVSS score of 5.5 (MEDIUM). 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 doubl...
How severe is CVE-2021-46904?
CVE-2021-46904 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-46904?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.