CVE-2023-52617

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: PCI: switchtec: corrige el bloqueo de stdev_release() después de una eliminación sorpresa en caliente. Puede ocurrir una eliminación en caliente del dispositivo PCI mientras stdev->cdev se mantiene abierto. La llamada a stdev_release() ocurre durante el cierre o la salida, en un punto mucho más allá de switchtec_pci_remove(). De lo contrario, la última referencia desaparecería con el put_device() final, justo antes del retorno. En ese momento posterior, la limpieza devm ya eliminó la asignación stdev->mmio_mrpc. Además, la referencia stdev->pdev no se contaba. Por lo tanto, en modo DMA, iowrite32() en stdev_release() causará un error de página fatal, y el dma_free_coherent() posterior, si se alcanza, pasaría un puntero &stdev->pdev->dev obsoleto. Para solucionarlo, mueva el apagado de MRPC DMA a switchtec_pci_remove(), después de stdev_kill(). Contar stdev->pdev ref ahora es opcional, pero puede evitar accidentes futuros. Reproducible a través del script en https://lore.kernel.org/r/20231113212150.96410-1-dns@arista.com

In the Linux kernel, the following vulnerability has been resolved: PCI: switchtec: Fix stdev_release() crash after surprise hot remove A PCI device hot removal may occur while stdev->cdev is held open. The call to stdev_release() then happens during close or exit, at a point way past switchtec_pci_remove(). Otherwise the last ref would vanish with the trailing put_device(), just before return. At that later point in time, the devm cleanup has already removed the stdev->mmio_mrpc mapping. Also, the stdev->pdev reference was not a counted one. Therefore, in DMA mode, the iowrite32() in stdev_release() will cause a fatal page fault, and the subsequent dma_free_coherent(), if reached, would pass a stale &stdev->pdev->dev pointer. Fix by moving MRPC DMA shutdown into switchtec_pci_remove(), after stdev_kill(). Counting the stdev->pdev ref is now optional, but may prevent future accidents. Reproducible via the script at https://lore.kernel.org/r/20231113212150.96410-1-dns@arista.com

It was discovered that the Open vSwitch implementation in the Linux kernel could overflow its stack during recursive action operations under certain conditions. A local 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.