"value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsch/netem: fix use after free in netem_dequeue\n\nIf netem_dequeue() enqueues packet to inner qdisc and that qdisc\nreturns __NET_XMIT_STOLEN. The packet is dropped but\nqdisc_tree_reduce_backlog() is not called to update the parent's\nq.qlen, leading to the similar use-after-free as Commit\ne04991a48dbaf382 (\"netem: fix return value if duplicate enqueue\nfails\")\n\nCommands to trigger KASAN UaF:\n\nip link add type dummy\nip link set lo up\nip link set dummy0 up\ntc qdisc add dev lo parent root handle 1: drr\ntc filter add dev lo parent 1: basic classid 1:1\ntc class add dev lo classid 1:1 drr\ntc qdisc add dev lo parent 1:1 handle 2: netem\ntc qdisc add dev lo parent 2: handle 3: drr\ntc filter add dev lo parent 3: basic classid 3:1 action mirred egress\nredirect dev dummy0\ntc class add dev lo classid 3:1 drr\nping -c1 -W0.01 localhost # Trigger bug\ntc class del dev lo classid 1:1\ntc class add dev lo classid 1:1 drr\nping -c1 -W0.01 localhost # UaF"
"value":"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: sch/netem: se corrige el use after free en netem_dequeue si netem_dequeue() pone en cola el paquete en la qdisc interna y esa qdisc devuelve __NET_XMIT_STOLEN. El paquete se descarta pero no se llama a qdisc_tree_reduce_backlog() para actualizar el q.qlen del padre, lo que lleva a un use after free similar al Commit e04991a48dbaf382 (\"netem: corrige el valor de retorno si falla la puesta en cola duplicada\") Comandos para activar KASAN UaF: ip link add type dummy ip link set lo up ip link set dummy0 up tc qdisc add dev lo parent root handle 1: drr tc filter add dev lo parent 1: basic classid 1:1 tc class add dev lo classid 1:1 drr tc qdisc add dev lo parent 1:1 handle 2: netem tc qdisc add dev lo parent 2: handle 3: drr tc filter add dev lo parent 3: basic classid 3:1 action mirred egress redirect dev dummy0 tc class add dev lo classid 3:1 drr ping -c1 -W0.01 localhost # Desencadenador de error tc class del dev lo classid 1:1 tc class add dev lo classid 1:1 drr ping -c1 -W0.01 localhost # UaF"