In the Linux kernel, the following vulnerability has been resolved: media: dvb-core: fix wrong reinitialization of ringbuffer on reopen dvb_dvr_open() calls dvb_ringbuffer_init() when a new reader opens the DVR device. dvb_ringbuffer_init() calls init_waitqueue_head(), which reinitializes the waitqueue list head to empty. Since dmxdev->dvr_buffer.queue is a shared waitqueue (all opens of the same DVR device share it), this orphans any existing waitqueue entries from io_uring poll or epoll, leaving them with stale prev/next pointers while the list head is reset to {self, self}. The waitqueue and spinlock in dvr_buffer are already properly initialized once in dvb_dmxdev_init(). The open path only needs to reset the buffer data pointer, size, and read/write positions. Replace the dvb_ringbuffer_init() call in dvb_dvr_open() with direct assignment of data/size and a call to dvb_ringbuffer_reset(), which properly resets pread, pwrite, and error with correct memory ordering without touching the waitqueue or spinlock.
En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta: media: dvb-core: corrige la reinicialización incorrecta del búfer circular al reabrir dvb_dvr_open() llama a dvb_ringbuffer_init() cuando un nuevo lector abre el dispositivo DVR. dvb_ringbuffer_init() llama a init_waitqueue_head(), lo que reinicializa la cabecera de la lista de la cola de espera a vacía. Dado que dmxdev->dvr_buffer.queue es una cola de espera compartida (todas las aperturas del mismo dispositivo DVR la comparten), esto deja huérfanas las entradas existentes de la cola de espera de io_uring poll o epoll, dejándolas con punteros prev/next obsoletos mientras la cabecera de la lista se restablece a {self, self}. La cola de espera y el spinlock en dvr_buffer ya están correctamente inicializados una vez en dvb_dmxdev_init(). La ruta de apertura solo necesita restablecer el puntero de datos del búfer, el tamaño y las posiciones de lectura/escritura. Reemplace la llamada a dvb_ringbuffer_init() en dvb_dvr_open() con la asignación directa de datos/tamaño y una llamada a dvb_ringbuffer_reset(), que restablece correctamente pread, pwrite y error con el ordenamiento de memoria correcto sin tocar la cola de espera o el spinlock.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | LOCAL |
|---|---|
| Attack Complexity | LOW |
| Privileges Required | LOW |
| User Interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality Impact | HIGH |
| Integrity Impact | HIGH |
| Availability Impact | HIGH |
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Type: Secondary
Exploitability Score: 1.8
Impact Score: 5.9
| Source | Type | Description |
|---|---|---|
| [email protected] | Primary |
en
NVD-CWE-noinfo
|
| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd340a31940> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd34b8daec0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd340af5600> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd34088f700> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd340a314c0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd340a329c0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd34088f800> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7fd34088dd00> | 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:7.0:rc1:*:*:*:*:*:* |