"value":"In the Linux kernel, the following vulnerability has been resolved:\n\nwatch_queue: Fix filter limit check\n\nIn watch_queue_set_filter(), there are a couple of places where we check\nthat the filter type value does not exceed what the type_filter bitmap\ncan hold. One place calculates the number of bits by:\n\n if (tf[i].type >= sizeof(wfilter->type_filter) * 8)\n\nwhich is fine, but the second does:\n\n if (tf[i].type >= sizeof(wfilter->type_filter) * BITS_PER_LONG)\n\nwhich is not. This can lead to a couple of out-of-bounds writes due to\na too-large type:\n\n (1) __set_bit() on wfilter->type_filter\n (2) Writing more elements in wfilter->filters[] than we allocated.\n\nFix this by just using the proper WATCH_TYPE__NR instead, which is the\nnumber of types we actually know about.\n\nThe bug may cause an oops looking something like:\n\n BUG: KASAN: slab-out-of-bounds in watch_queue_set_filter+0x659/0x740\n Write of size 4 at addr ffff88800d2c66bc by task watch_queue_oob/611\n ...\n Call Trace:\n <TASK>\n dump_stack_lvl+0x45/0x59\n print_address_description.constprop.0+0x1f/0x150\n ...\n kasan_report.cold+0x7f/0x11b\n ...\n watch_queue_set_filter+0x659/0x740\n ...\n __x64_sys_ioctl+0x127/0x190\n do_syscall_64+0x43/0x90\n entry_SYSCALL_64_after_hwframe+0x44/0xae\n\n Allocated by task 611:\n kasan_save_stack+0x1e/0x40\n __kasan_kmalloc+0x81/0xa0\n watch_queue_set_filter+0x23a/0x740\n __x64_sys_ioctl+0x127/0x190\n do_syscall_64+0x43/0x90\n entry_SYSCALL_64_after_hwframe+0x44/0xae\n\n The buggy address belongs to the object at ffff88800d2c66a0\n which belongs to the cache kmalloc-32 of size 32\n The buggy address is located 28 bytes inside of\n 32-byte region [ffff88800d2c66a0, ffff88800d2c66c0)"
"value":"En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: watch_queue: corrige la verificaci\u00f3n del l\u00edmite del filtro En watch_queue_set_filter(), hay un par de lugares donde verificamos que el valor del tipo de filtro no exceda lo que puede contener el mapa de bits type_filter. Un lugar calcula el n\u00famero de bits mediante: if (tf[i].type >= sizeof(wfilter->type_filter) * 8) lo cual est\u00e1 bien, pero el segundo s\u00ed: if (tf[i].type >= sizeof( wfilter->type_filter) * BITS_PER_LONG) que no lo es. Esto puede provocar un par de escrituras fuera de los l\u00edmites debido a un tipo demasiado grande: (1) __set_bit() en wfilter->type_filter (2) Escribir m\u00e1s elementos en wfilter->filters[] de los que asignamos. Solucione este problema simplemente usando el WATCH_TYPE__NR adecuado, que es la cantidad de tipos que realmente conocemos. El error puede provocar un error parecido a: ERROR: KASAN: slab-out-of-bounds in watch_queue_set_filter+0x659/0x740 Escritura de tama\u00f1o 4 en la direcci\u00f3n ffff88800d2c66bc mediante la tarea watch_queue_oob/611... Seguimiento de llamadas: dump_stack_lvl+ 0x45/0x59 print_address_description.constprop.0+0x1f/0x150 ... kasan_report.cold+0x7f/0x11b ... watch_queue_set_filter+0x659/0x740 ... __x64_sys_ioctl+0x127/0x190 do_syscall_64+0x43/0x90 entrada_ SYSCALL_64_after_hwframe+0x44/0xae Asignado por tarea 611: kasan_save_stack+0x1e/0x40 __kasan_kmalloc+0x81/0xa0 watch_queue_set_filter+0x23a/0x740 __x64_sys_ioctl+0x127/0x190 do_syscall_64+0x43/0x90 Entry_SYSCALL_64_after_hwframe+0x 44/0xae La direcci\u00f3n con errores pertenece al objeto en ffff88800d2c66a0 que pertenece al cach\u00e9 kmalloc-32 de tama\u00f1o 32 La direcci\u00f3n con errores se encuentra a 28 bytes dentro de la regi\u00f3n de 32 bytes [ffff88800d2c66a0, ffff88800d2c66c0)"
