Описание
In the Linux kernel, the following vulnerability has been resolved:
net/sched: cls_bpf: prevent unbounded recursion in offload rollback
Quan Sun reported [1] a stack overflow in cls_bpf_offload_cmd().
Reproducer on netdevsim: add a skip_sw cls_bpf filter, set the
bpf_tc_accept debugfs knob to 0, then tc filter replace. The replace
calls tc_setup_cb_replace() which fails. cls_bpf_offload_cmd() then
swaps prog/oldprog and recursively calls itself to roll back. But
bpf_tc_accept=0 makes the rollback fail too, which triggers yet another
rollback frame with the same arguments, and so on until the stack is
exhausted.
bpf_tc_accept is just a convenient knob for the reproducer. Any driver whose tc_setup_cb_replace() fails twice in a row can hit the same loop, so this is not a netdevsim-only issue.
Two ways to fix it:
- Have the rollback call tc_setup_cb_add() on oldprog instead of re-entering cls_bpf_offload_cmd().
- Mark the rollback frame with a flag and skip a second-leve
Ссылки
EPSS
Дефекты
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_bpf: prevent unbounded recursion in offload rollback Quan Sun reported [1] a stack overflow in cls_bpf_offload_cmd(). Reproducer on netdevsim: add a skip_sw cls_bpf filter, set the bpf_tc_accept debugfs knob to 0, then `tc filter replace`. The replace calls tc_setup_cb_replace() which fails. cls_bpf_offload_cmd() then swaps prog/oldprog and recursively calls itself to roll back. But bpf_tc_accept=0 makes the rollback fail too, which triggers yet another rollback frame with the same arguments, and so on until the stack is exhausted. bpf_tc_accept is just a convenient knob for the reproducer. Any driver whose tc_setup_cb_replace() fails twice in a row can hit the same loop, so this is not a netdevsim-only issue. Two ways to fix it: 1) Have the rollback call tc_setup_cb_add() on oldprog instead of re-entering cls_bpf_offload_cmd(). 2) Mark the rollback frame with a flag and skip a second-level rollback f...
In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_bpf: prevent unbounded recursion in offload rollback Quan Sun reported [1] a stack overflow in cls_bpf_offload_cmd(). Reproducer on netdevsim: add a skip_sw cls_bpf filter, set the bpf_tc_accept debugfs knob to 0, then `tc filter replace`. The replace calls tc_setup_cb_replace() which fails. cls_bpf_offload_cmd() then swaps prog/oldprog and recursively calls itself to roll back. But bpf_tc_accept=0 makes the rollback fail too, which triggers yet another rollback frame with the same arguments, and so on until the stack is exhausted. bpf_tc_accept is just a convenient knob for the reproducer. Any driver whose tc_setup_cb_replace() fails twice in a row can hit the same loop, so this is not a netdevsim-only issue. Two ways to fix it: 1) Have the rollback call tc_setup_cb_add() on oldprog instead of re-entering cls_bpf_offload_cmd(). 2) Mark the rollback frame with a flag and skip a second-level rollback f...
In the Linux kernel, the following vulnerability has been resolved: n ...
In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_bpf: prevent unbounded recursion in offload rollback Quan Sun reported [1] a stack overflow in cls_bpf_offload_cmd(). Reproducer on netdevsim: add a skip_sw cls_bpf filter, set the bpf_tc_accept debugfs knob to 0, then `tc filter replace`. The replace calls tc_setup_cb_replace() which fails. cls_bpf_offload_cmd() then swaps prog/oldprog and recursively calls itself to roll back. But bpf_tc_accept=0 makes the rollback fail too, which triggers yet another rollback frame with the same arguments, and so on until the stack is exhausted. bpf_tc_accept is just a convenient knob for the reproducer. Any driver whose tc_setup_cb_replace() fails twice in a row can hit the same loop, so this is not a netdevsim-only issue. Two ways to fix it: 1) Have the rollback call tc_setup_cb_add() on oldprog instead of re-entering cls_bpf_offload_cmd(). 2) Mark the rollback frame with a flag and skip a second-l...
EPSS