CVE-2021-47491
mm: khugepaged: skip huge page collapse for special files
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
In the Linux kernel, the following vulnerability has been resolved:
mm: khugepaged: skip huge page collapse for special files
The read-only THP for filesystems will collapse THP for files opened
readonly and mapped with VM_EXEC. The intended usecase is to avoid TLB
misses for large text segments. But it doesn't restrict the file types
so a THP could be collapsed for a non-regular file, for example, block
device, if it is opened readonly and mapped with EXEC permission. This
may cause bugs, like [1] and [2].
This is definitely not the intended usecase, so just collapse THP for
regular files in order to close the attack surface.
[shy828301@gmail.com: fix vm_file check [3]]
En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mm: khugepaged: omitir el colapso de página enorme para archivos especiales El THP de solo lectura para sistemas de archivos colapsará el THP para archivos abiertos de solo lectura y asignados con VM_EXEC. El caso de uso previsto es evitar errores de TLB en segmentos de texto grandes. Pero no restringe los tipos de archivos, por lo que un THP podría contraerse para un archivo no normal, por ejemplo, un dispositivo de bloqueo, si se abre en modo de solo lectura y se asigna con permiso EXEC. Esto puede causar errores, como [1] y [2]. Definitivamente este no es el caso de uso previsto, así que simplemente contraiga THP para archivos normales para cerrar la superficie de ataque. [shy828301@gmail.com: corrige la verificación de vm_file [3]]
CVSS Scores
SSVC
- Decision:Track
Timeline
- 2024-05-22 CVE Reserved
- 2024-05-22 CVE Published
- 2024-05-23 EPSS Updated
- 2024-12-19 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
- CWE-664: Improper Control of a Resource Through its Lifetime
CAPEC
References (6)
URL | Tag | Source |
---|---|---|
https://git.kernel.org/stable/c/99cb0dbd47a15d395bf3faa78dc122bc5efe3fc0 | Vuln. Introduced |
URL | Date | SRC |
---|
URL | Date | SRC |
---|---|---|
https://access.redhat.com/security/cve/CVE-2021-47491 | 2024-08-08 | |
https://bugzilla.redhat.com/show_bug.cgi?id=2282925 | 2024-08-08 |
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" | >= 5.4 < 5.10.78 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 5.10.78" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.4 < 5.14.16 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 5.14.16" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.4 < 5.15 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4 < 5.15" | en |
Affected
|