"value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnull_blk: fix null-ptr-dereference while configuring 'power' and 'submit_queues'\n\nWriting 'power' and 'submit_queues' concurrently will trigger kernel\npanic:\n\nTest script:\n\nmodprobe null_blk nr_devices=0\nmkdir -p /sys/kernel/config/nullb/nullb0\nwhile true; do echo 1 > submit_queues; echo 4 > submit_queues; done &\nwhile true; do echo 1 > power; echo 0 > power; done\n\nTest result:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000148\nOops: 0000 [#1] PREEMPT SMP\nRIP: 0010:__lock_acquire+0x41d/0x28f0\nCall Trace:\n <TASK>\n lock_acquire+0x121/0x450\n down_write+0x5f/0x1d0\n simple_recursive_removal+0x12f/0x5c0\n blk_mq_debugfs_unregister_hctxs+0x7c/0x100\n blk_mq_update_nr_hw_queues+0x4a3/0x720\n nullb_update_nr_hw_queues+0x71/0xf0 [null_blk]\n nullb_device_submit_queues_store+0x79/0xf0 [null_blk]\n configfs_write_iter+0x119/0x1e0\n vfs_write+0x326/0x730\n ksys_write+0x74/0x150\n\nThis is because del_gendisk() can concurrent with\nblk_mq_update_nr_hw_queues():\n\nnullb_device_power_store\tnullb_apply_submit_queues\n null_del_dev\n del_gendisk\n\t\t\t\t nullb_update_nr_hw_queues\n\t\t\t\t if (!dev->nullb)\n\t\t\t\t // still set while gendisk is deleted\n\t\t\t\t return 0\n\t\t\t\t blk_mq_update_nr_hw_queues\n dev->nullb = NULL\n\nFix this problem by resuing the global mutex to protect\nnullb_device_power_store() and nullb_update_nr_hw_queues() from configfs."
"value":"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: null_blk: corrige la dereferencia null-ptr al configurar 'power' y 'submit_queues'. Escribir 'power' y 'submit_queues' simult\u00e1neamente provocar\u00e1 un p\u00e1nico en el kernel: Script de prueba: modprobe null_blk nr_devices= 0 mkdir -p /sys/kernel/config/nullb/nullb0 mientras sea verdadero; hacer eco 1 > enviar_queues; eco 4 > enviar_colas; hecho y mientras sea cierto; hacer eco 1 > potencia; eco 0 > potencia; hecho Resultado de la prueba: ERROR: desreferencia del puntero NULL del kernel, direcci\u00f3n: 0000000000000148 Ups: 0000 [#1] RIP SMP PREEMPLEADO: 0010:__lock_acquire+0x41d/0x28f0 Seguimiento de llamada: lock_acquire+0x121/0x450 down_write+0x5f/0x1d0 simple_recursive _eliminaci\u00f3n+ 0x12f/0x5c0 blk_mq_debugfs_unregister_hctxs+0x7c/0x100 blk_mq_update_nr_hw_queues+0x4a3/0x720 nullb_update_nr_hw_queues+0x71/0xf0 [null_blk] /0xf0 [null_blk] configfs_write_iter+0x119/0x1e0 vfs_write+0x326/0x730 ksys_write+0x74/0x150 Esto se debe a que del_gendisk() puede concurrente con blk_mq_update_nr_hw_queues(): nullb_device_power_store nullb_apply_submit_queues null_del_dev del_gendisk nullb_update_nr_hw_queues if (!dev->nullb) // todav\u00eda est\u00e1 configurado mientras se elimina gendisk return 0 blk_mq_update_nr_hw_queues dev->nullb = NULL Fix este problema reutilizando el mutex global para proteger nullb_device_power_store() y nullb_update_nr_hw_queues() de configfs."