CVE-2023-52492

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: dmaengine: corrige el puntero NULL en la función de cancelación del registro del canal __dma_async_device_channel_register() puede fallar. En caso de falla, chan->local se libera (con free_percpu()) y chan->local se anula. Cuando se llama a dma_async_device_unregister() (debido a una API administrada o intencionalmente por el controlador del controlador DMA), los canales se anulan incondicionalmente, lo que lleva a este puntero NULL: [1.318693] No se puede manejar la desreferencia del puntero NULL del kernel en la dirección virtual 00000000000000d0 [...] [ 1.484499] Seguimiento de llamadas: [ 1.486930] device_del+0x40/0x394 [ 1.490314] device_unregister+0x20/0x7c [ 1.494220] __dma_async_device_channel_unregister+0x68/0xc0 Mire la ruta de error de la función dma_async_device_register(), cancelación del registro del dispositivo La ración se realiza sólo si chan->local es no nulo. Luego agregue la misma condición al comienzo de la función __dma_async_device_channel_unregister(), para evitar problemas de puntero NULL cualquiera que sea la API utilizada para alcanzar esta función.

In the Linux kernel, the following vulnerability has been resolved: dmaengine: fix NULL pointer in channel unregistration function __dma_async_device_channel_register() can fail. In case of failure, chan->local is freed (with free_percpu()), and chan->local is nullified. When dma_async_device_unregister() is called (because of managed API or intentionally by DMA controller driver), channels are unconditionally unregistered, leading to this NULL pointer: [ 1.318693] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000d0 [...] [ 1.484499] Call trace: [ 1.486930] device_del+0x40/0x394 [ 1.490314] device_unregister+0x20/0x7c [ 1.494220] __dma_async_device_channel_unregister+0x68/0xc0 Look at dma_async_device_register() function error path, channel device unregistration is done only if chan->local is not NULL. Then add the same condition at the beginning of __dma_async_device_channel_unregister() function, to avoid NULL pointer issue whatever the API used to reach this function.

Alon Zahavi discovered that the NVMe-oF/TCP subsystem in the Linux kernel did not properly validate H2C PDU data, leading to a null pointer dereference vulnerability. A remote attacker could use this to cause a denial of service. Sander Wiebing, Alvise de Faveri Tron, Herbert Bos, and Cristiano Giuffrida discovered that the Linux kernel mitigations for the initial Branch History Injection vulnerability were insufficient for Intel processors. A local attacker could potentially use this to expose sensitive information.