In the Linux kernel, the following vulnerability has been resolved: sch/netem: fix use after free in netem_dequeue If netem_dequeue() enqueues packet to inner qdisc and that qdisc returns __NET_XMIT_STOLEN. The packet is dropped but qdisc_tree_reduce_backlog() is not called to update the parent’s q.qlen, leading to the similar use-after-free as Commit e04991a48dbaf382 (“netem: fix return value if duplicate enqueue fails”) Commands to trigger 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 # Trigger bug tc class del dev lo classid 1:1 tc class add dev lo classid 1:1 drr ping -c1 -W0.01 localhost # UaF
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
Debian | 12 | all | linux | <= 6.1.106-3 | linux_6.1.106-3_all.deb |
Debian | 11 | all | linux | <= 5.10.223-1 | linux_5.10.223-1_all.deb |
Debian | 999 | all | linux | <= 6.10.9-1 | linux_6.10.9-1_all.deb |
Debian | 13 | all | linux | <= 6.10.9-1 | linux_6.10.9-1_all.deb |