In the Linux kernel, the following vulnerability has been resolved: __legitimize_mnt(): check for MNT_SYNC_UMOUNT should be under mount_lock ... or we risk stealing final mntput from sync umount - raising mnt_count after umount(2) has verified that victim is not busy, but before it has set MNT_SYNC_UMOUNT; in that case __legitimize_mnt() doesn't see that it's safe to quietly undo mnt_count increment and leaves dropping the reference to caller, where it'll be a full-blown mntput(). Check under mount_lock is needed; leaving the current one done before taking that makes no sense - it's nowhere near common enough to bother with.
En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: __legitimize_mnt(): la comprobación de MNT_SYNC_UMOUNT debe estar bajo mount_lock... o corremos el riesgo de robar la mntput final de sync umount, lo que genera mnt_count después de que umount(2) haya verificado que la víctima no está ocupada, pero antes de que haya establecido MNT_SYNC_UMOUNT. En ese caso, __legitimize_mnt() no considera que sea seguro deshacer silenciosamente el incremento de mnt_count y continúa eliminando la referencia al llamador, donde se ejecutará una mntput() completa. Es necesaria la comprobación bajo mount_lock; dejar la actual activada antes de tomarla no tiene sentido; no es lo suficientemente común como para molestarse en hacerlo.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
| Attack Vector | LOCAL |
|---|---|
| Attack Complexity | LOW |
| Privileges Required | LOW |
| User Interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality Impact | NONE |
| Integrity Impact | NONE |
| Availability Impact | HIGH |
| Source | Type | Description |
|---|---|---|
| [email protected] | Primary |
en
CWE-667
|
| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd38674df00> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd384e942c0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd368635100> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd368635780> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd36b8a4ec0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd36b8a70c0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd36b335180> | Operating System |
| linux | linux_kernel | 6.15 | <built-in method update of dict object at 0x7fd2a10d9e40> | Operating System |
| linux | linux_kernel | 6.15 | <built-in method update of dict object at 0x7fd3094e6700> | Operating System |
| linux | linux_kernel | 6.15 | <built-in method update of dict object at 0x7fd36b8a6ec0> | Operating System |
| linux | linux_kernel | 6.15 | <built-in method update of dict object at 0x7fd341756e00> | Operating System |
| linux | linux_kernel | 6.15 | <built-in method update of dict object at 0x7fd36a6d04c0> | Operating System |
| debian | debian_linux | 11.0 | <built-in method update of dict object at 0x7fd386754f40> | Operating System |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.15:rc1:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.15:rc2:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.15:rc3:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.15:rc4:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.15:rc5:*:*:*:*:*:* |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* |