CVE-2024-26671

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: blk-mq: corrige el bloqueo de IO de la carrera de activación del mapa de bits En blk_mq_mark_tag_wait(), __add_wait_queue() se puede reordenar con el siguiente blk_mq_get_driver_tag() en caso de que se produzca un error en la etiqueta del controlador. Luego, en __sbitmap_queue_wake_up(), waitqueue_active() puede no observar al camarero agregado en blk_mq_mark_tag_wait() y no despertar nada, mientras tanto, blk_mq_mark_tag_wait() no puede obtener la etiqueta del controlador correctamente. Este problema se puede reproducir ejecutando la siguiente prueba en bucle, y se puede observar un bloqueo de fio en < 30 minutos cuando lo ejecuto en mi máquina virtual de prueba en una computadora portátil. modprobe -r scsi_debug modprobe scsi_debug delay=0 dev_size_mb=4096 max_queue=1 host_max_queue=1 submit_queues=4 dev=`ls -d /sys/bus/pseudo/drivers/scsi_debug/adapter*/host*/target*/*/block /* | cabeza -1 | xargs basename` fio --filename=/dev/"$dev" --direct=1 --rw=randrw --bs=4k --io Depth=1 \ --runtime=100 --numjobs=40 --time_based - -name=test \ --ioengine=libaio Solucione el problema agregando una barrera explícita en blk_mq_mark_tag_wait(), lo cual está bien en caso de quedarse sin etiqueta.

In the Linux kernel, the following vulnerability has been resolved: blk-mq: fix IO hang from sbitmap wakeup race In blk_mq_mark_tag_wait(), __add_wait_queue() may be re-ordered with the following blk_mq_get_driver_tag() in case of getting driver tag failure. Then in __sbitmap_queue_wake_up(), waitqueue_active() may not observe the added waiter in blk_mq_mark_tag_wait() and wake up nothing, meantime blk_mq_mark_tag_wait() can't get driver tag successfully. This issue can be reproduced by running the following test in loop, and fio hang can be observed in < 30min when running it on my test VM in laptop. modprobe -r scsi_debug modprobe scsi_debug delay=0 dev_size_mb=4096 max_queue=1 host_max_queue=1 submit_queues=4 dev=`ls -d /sys/bus/pseudo/drivers/scsi_debug/adapter*/host*/target*/*/block/* | head -1 | xargs basename` fio --filename=/dev/"$dev" --direct=1 --rw=randrw --bs=4k --iodepth=1 \ --runtime=100 --numjobs=40 --time_based --name=test \ --ioengine=libaio Fix the issue by adding one explicit barrier in blk_mq_mark_tag_wait(), which is just fine in case of running out of tag.

Alon Zahavi discovered that the NVMe-oF/TCP subsystem in the Linux kernel did not properly validate H2C PDU data, leading to a null pointer dereference vulnerability. A remote 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.