"value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/gup: handle NULL pages in unpin_user_pages()\n\nThe recent addition of \"pofs\" (pages or folios) handling to gup has a\nflaw: it assumes that unpin_user_pages() handles NULL pages in the pages**\narray. That's not the case, as I discovered when I ran on a new\nconfiguration on my test machine.\n\nFix this by skipping NULL pages in unpin_user_pages(), just like\nunpin_folios() already does.\n\nDetails: when booting on x86 with \"numa=fake=2 movablecore=4G\" on Linux\n6.12, and running this:\n\n tools/testing/selftests/mm/gup_longterm\n\n...I get the following crash:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000008\nRIP: 0010:sanity_check_pinned_pages+0x3a/0x2d0\n...\nCall Trace:\n <TASK>\n ? __die_body+0x66/0xb0\n ? page_fault_oops+0x30c/0x3b0\n ? do_user_addr_fault+0x6c3/0x720\n ? irqentry_enter+0x34/0x60\n ? exc_page_fault+0x68/0x100\n ? asm_exc_page_fault+0x22/0x30\n ? sanity_check_pinned_pages+0x3a/0x2d0\n unpin_user_pages+0x24/0xe0\n check_and_migrate_movable_pages_or_folios+0x455/0x4b0\n __gup_longterm_locked+0x3bf/0x820\n ? mmap_read_lock_killable+0x12/0x50\n ? __pfx_mmap_read_lock_killable+0x10/0x10\n pin_user_pages+0x66/0xa0\n gup_test_ioctl+0x358/0xb20\n __se_sys_ioctl+0x6b/0xc0\n do_syscall_64+0x7b/0x150\n entry_SYSCALL_64_after_hwframe+0x76/0x7e"
"value":"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mm/gup: gestionar p\u00e1ginas NULL en unpin_user_pages() La reciente incorporaci\u00f3n dla gesti\u00f3n de \"pofs\" (p\u00e1ginas o folios) a gup tiene un defecto: supone que unpin_user_pages() gestiona p\u00e1ginas NULL en la matriz pages**. Ese no es el caso, como descubr\u00ed cuando ejecut\u00e9 una nueva configuraci\u00f3n en mi m\u00e1quina de prueba. Solucione esto omitiendo las p\u00e1ginas NULL en unpin_user_pages(), tal como ya lo hace unpin_folios(). Detalles: al arrancar en x86 con \"numa=fake=2 movablecore=4G\" en Linux 6.12, y ejecutar esto: tools/testing/selftests/mm/gup_longterm ... obtengo el siguiente fallo: ERROR: desreferencia de puntero NULL del n\u00facleo, direcci\u00f3n: 0000000000000008 RIP: 0010:sanity_check_pinned_pages+0x3a/0x2d0 ... Seguimiento de llamadas: ? __die_body+0x66/0xb0 ? page_fault_oops+0x30c/0x3b0 ? do_user_addr_fault+0x6c3/0x720 ? irqentry_enter+0x34/0x60 ? exc_page_fault+0x68/0x100 ? asm_exc_page_fault+0x22/0x30 ? comprobaci\u00f3n de integridad de p\u00e1ginas fijadas+0x3a/0x2d0 desanclar p\u00e1ginas de usuario+0x24/0xe0 comprobar y migrar p\u00e1ginas o folios movibles+0x455/0x4b0 __gup_longterm_locked+0x3bf/0x820 ? mmap_read_lock_killable+0x12/0x50 ? __pfx_mmap_read_lock_killable+0x10/0x10 pin_usuario_p\u00e1ginas+0x66/0xa0 gup_test_ioctl+0x358/0xb20 __se_sys_ioctl+0x6b/0xc0 hacer_llamada_al_sistema_64+0x7b/0x150 entrada_SYSCALL_64_despu\u00e9s_de_hwframe+0x76/0x7e"