CVE-2021-46904

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2021-46904
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.

5.5 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/145c89c441d27696961752bf51b323f347601bee Patch
https://git.kernel.org/stable/c/388d05f70f1ee0cac4a2068fd295072f1a44152a Patch
https://git.kernel.org/stable/c/4a2933c88399c0ebc738db39bbce3ae89786d723 Patch
https://git.kernel.org/stable/c/8a12f8836145ffe37e9c8733dce18c22fb668b66 Patch
https://git.kernel.org/stable/c/92028d7a31e55d53e41cff679156b9432cffcb36 Patch
https://git.kernel.org/stable/c/a462067d7c8e6953a733bf5ade8db947b1bb5449 Patch
https://git.kernel.org/stable/c/caf5ac93b3b5d5fac032fc11fbea680e115421b4 Patch
https://git.kernel.org/stable/c/dc195928d7e4ec7b5cfc6cd10dc4c8d87a7c72ac Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
History

17 Apr 2024, 19:33

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/145c89c441d27696961752bf51b323f347601bee - () https://git.kernel.org/stable/c/145c89c441d27696961752bf51b323f347601bee - Patch
References () https://git.kernel.org/stable/c/388d05f70f1ee0cac4a2068fd295072f1a44152a - () https://git.kernel.org/stable/c/388d05f70f1ee0cac4a2068fd295072f1a44152a - Patch
References () https://git.kernel.org/stable/c/4a2933c88399c0ebc738db39bbce3ae89786d723 - () https://git.kernel.org/stable/c/4a2933c88399c0ebc738db39bbce3ae89786d723 - Patch
References () https://git.kernel.org/stable/c/8a12f8836145ffe37e9c8733dce18c22fb668b66 - () https://git.kernel.org/stable/c/8a12f8836145ffe37e9c8733dce18c22fb668b66 - Patch
References () https://git.kernel.org/stable/c/92028d7a31e55d53e41cff679156b9432cffcb36 - () https://git.kernel.org/stable/c/92028d7a31e55d53e41cff679156b9432cffcb36 - Patch
References () https://git.kernel.org/stable/c/a462067d7c8e6953a733bf5ade8db947b1bb5449 - () https://git.kernel.org/stable/c/a462067d7c8e6953a733bf5ade8db947b1bb5449 - Patch
References () https://git.kernel.org/stable/c/caf5ac93b3b5d5fac032fc11fbea680e115421b4 - () https://git.kernel.org/stable/c/caf5ac93b3b5d5fac032fc11fbea680e115421b4 - Patch
References () https://git.kernel.org/stable/c/dc195928d7e4ec7b5cfc6cd10dc4c8d87a7c72ac - () https://git.kernel.org/stable/c/dc195928d7e4ec7b5cfc6cd10dc4c8d87a7c72ac - Patch
Summary
  • (es) En el kernel de Linux, se resolvió la siguiente vulnerabilidad: net: hso: corrige null-ptr-deref durante la cancelación del registro del dispositivo tty. Múltiples ttys intentan reclamar el mismo número menor, lo que provoca una doble cancelación del registro del mismo dispositivo. La primera cancelación del registro se realiza correctamente, pero la siguiente genera un null-ptr-deref. La función get_free_serial_index() devuelve un número menor disponible pero no lo asigna inmediatamente. La asignación la realiza la persona que llama más tarde. Pero antes de esta asignación, las llamadas a get_free_serial_index() devolverían el mismo número menor. Solucione este problema modificando get_free_serial_index para asignar el número menor inmediatamente después de que se encuentre uno y cámbiele el nombre a get_minor() para reflejar mejor lo que hace. De manera similar, cambie el nombre de set_serial_by_index() a release_minor() y modifíquelo para liberar el número menor del hso_serial dado. Cada get_minor() debe tener la llamada release_minor() correspondiente.
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
CWE CWE-476
First Time Linux linux Kernel
Linux
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 5.5

26 Feb 2024, 16:32

Type Values Removed Values Added
New CVE
Information

Published : 2024-02-26 16:27

Updated : 2024-04-17 19:33

NVD link : CVE-2021-46904

Mitre link : CVE-2021-46904

CVE.ORG link : CVE-2021-46904

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-476

NULL Pointer Dereference