CVE-2021-47342

ext4: fix possible UAF when remounting r/o a mmp-protected file system

Severity Score

"-"

*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

In the Linux kernel, the following vulnerability has been resolved:

ext4: fix possible UAF when remounting r/o a mmp-protected file system

After commit 618f003199c6 ("ext4: fix memory leak in
ext4_fill_super"), after the file system is remounted read-only, there
is a race where the kmmpd thread can exit, causing sbi->s_mmp_tsk to
point at freed memory, which the call to ext4_stop_mmpd() can trip
over.

Fix this by only allowing kmmpd() to exit when it is stopped via
ext4_stop_mmpd().

Bug-Report-Link: <20210629143603.2166962-1-yebin10@huawei.com>

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ext4: corrige posible UAF al remontar el sistema de archivos protegido por r/oa mmp. Después del commit 618f003199c6 ("ext4: corrige la pérdida de memoria en ext4_fill_super"), después de que se vuelve a montar el sistema de archivos solo que hay una ejecución donde el hilo kmmpd puede salir, causando que sbi->s_mmp_tsk apunte a la memoria liberada, con la que la llamada a ext4_stop_mmpd() puede tropezar. Solucione este problema permitiendo que kmmpd() salga solo cuando se detiene a través de ext4_stop_mmpd(). Enlace de informe de error: <20210629143603.2166962-1-yebin10@huawei.com>

*Credits: N/A

CVSS Scores

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Scope

Confidentiality

Integrity

Availability

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-05-21 CVE Reserved
2024-05-21 CVE Published
2024-05-22 EPSS Updated
2024-08-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (3)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/b663890d854403e566169f7e90aed5cd6ff64f6b	2021-11-02
https://git.kernel.org/stable/c/7ed572cdf11081f8f9e07abd4bea56a3f2c4edbd	2021-07-19
https://git.kernel.org/stable/c/61bb4a1c417e5b95d9edb4f887f131de32e419cb	2021-07-08

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.10.77 Search vendor "Linux" for product "Linux Kernel" and version " < 5.10.77"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.13.3 Search vendor "Linux" for product "Linux Kernel" and version " < 5.13.3"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.14 Search vendor "Linux" for product "Linux Kernel" and version " < 5.14"		en		Affected