"value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/fbdev-dma: Only set smem_start is enable per module option\n\nOnly export struct fb_info.fix.smem_start if that is required by the\nuser and the memory does not come from vmalloc().\n\nSetting struct fb_info.fix.smem_start breaks systems where DMA\nmemory is backed by vmalloc address space. An example error is\nshown below.\n\n[ 3.536043] ------------[ cut here ]------------\n[ 3.540716] virt_to_phys used for non-linear address: 000000007fc4f540 (0xffff800086001000)\n[ 3.552628] WARNING: CPU: 4 PID: 61 at arch/arm64/mm/physaddr.c:12 __virt_to_phys+0x68/0x98\n[ 3.565455] Modules linked in:\n[ 3.568525] CPU: 4 PID: 61 Comm: kworker/u12:5 Not tainted 6.6.23-06226-g4986cc3e1b75-dirty #250\n[ 3.577310] Hardware name: NXP i.MX95 19X19 board (DT)\n[ 3.582452] Workqueue: events_unbound deferred_probe_work_func\n[ 3.588291] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)\n[ 3.595233] pc : __virt_to_phys+0x68/0x98\n[ 3.599246] lr : __virt_to_phys+0x68/0x98\n[ 3.603276] sp : ffff800083603990\n[ 3.677939] Call trace:\n[ 3.680393] __virt_to_phys+0x68/0x98\n[ 3.684067] drm_fbdev_dma_helper_fb_probe+0x138/0x238\n[ 3.689214] __drm_fb_helper_initial_config_and_unlock+0x2b0/0x4c0\n[ 3.695385] drm_fb_helper_initial_config+0x4c/0x68\n[ 3.700264] drm_fbdev_dma_client_hotplug+0x8c/0xe0\n[ 3.705161] drm_client_register+0x60/0xb0\n[ 3.709269] drm_fbdev_dma_setup+0x94/0x148\n\nAdditionally, DMA memory is assumed to by contiguous in physical\naddress space, which is not guaranteed by vmalloc().\n\nResolve this by checking the module flag drm_leak_fbdev_smem when\nDRM allocated the instance of struct fb_info. Fbdev-dma then only\nsets smem_start only if required (via FBINFO_HIDE_SMEM_START). Also\nguarantee that the framebuffer is not located in vmalloc address\nspace."
"value":"En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: drm/fbdev-dma: solo configurar smem_start est\u00e1 habilitado por opci\u00f3n de m\u00f3dulo. Solo exporte la estructura fb_info.fix.smem_start si as\u00ed lo requiere el usuario y la memoria no proviene de vmalloc( ). La configuraci\u00f3n de struct fb_info.fix.smem_start interrumpe los sistemas donde la memoria DMA est\u00e1 respaldada por el espacio de direcciones vmalloc. A continuaci\u00f3n se muestra un error de ejemplo. [3.536043] ------------[ cortar aqu\u00ed ]------------ [ 3.540716] virt_to_phys usado para direcciones no lineales: 000000007fc4f540 (0xffff800086001000) [ 3.552628] ADVERTENCIA : CPU: 4 PID: 61 en arch/arm64/mm/physaddr.c:12 __virt_to_phys+0x68/0x98 [ 3.565455] M\u00f3dulos vinculados en: [ 3.568525] CPU: 4 PID: 61 Comm: kworker/u12:5 No contaminado 6.6 .23-06226-g4986cc3e1b75-dirty #250 [ 3.577310] Nombre de hardware: placa NXP i.MX95 19X19 (DT) [ 3.582452] Cola de trabajo: events_unbound deferred_probe_work_func [ 3.588291] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT- SSBS BTYPE=--) [ 3.595233] pc : __virt_to_phys+0x68/0x98 [ 3.599246] lr : __virt_to_phys+0x68/0x98 [ 3.603276] sp : ffff800083603990 [ 3.677939] Rastreo de llamadas: [ 3.68039 3] __virt_to_phys+0x68/0x98 [ 3.684067] drm_fbdev_dma_helper_fb_probe +0x138/0x238 [ 3.689214] __drm_fb_helper_initial_config_and_unlock+0x2b0/0x4c0 [ 3.695385] drm_fb_helper_initial_config+0x4c/0x68 [ 3.700264] xe0 [ 3.705161] drm_client_register+0x60/0xb0 [ 3.709269] drm_fbdev_dma_setup+0x94/0x148 Adem\u00e1s, se supone memoria DMA a por contiguo en el espacio de direcciones f\u00edsicas, lo cual no est\u00e1 garantizado por vmalloc(). Resuelva esto verificando el indicador del m\u00f3dulo drm_leak_fbdev_smem cuando DRM asign\u00f3 la instancia de la estructura fb_info. Luego, Fbdev-dma solo configura smem_start solo si es necesario (a trav\u00e9s de FBINFO_HIDE_SMEM_START). Tambi\u00e9n garantice que el framebuffer no est\u00e9 ubicado en el espacio de direcciones vmalloc."