CVE-2026-23359

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix stack-out-of-bounds write in devmap get_upper_ifindexes() iterates over all upper devices and writes their indices into an array without checking bounds. Also the callers assume that the max number of upper devices is MAX_NEST_DEV and allocate excluded_devices[1+MAX_NEST_DEV] on the stack, but that assumption is not correct and the number of upper devices could be larger than MAX_NEST_DEV (e.g., many macvlans), causing a stack-out-of-bounds write. Add a max parameter to get_upper_ifindexes() to avoid the issue. When there are too many upper devices, return -EOVERFLOW and abort the redirect. To reproduce, create more than MAX_NEST_DEV(8) macvlans on a device with an XDP program attached using BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS. Then send a packet to the device to trigger the XDP redirect path.

• linux linux kernel (>= 5.15.1 < 5.15.203) • linux linux kernel (>= 5.16 < 6.1.167) • linux linux kernel (>= 6.2 < 6.6.130) • linux linux kernel (>= 6.7 < 6.12.77) • linux linux kernel (>= 6.13 < 6.18.17) • linux linux kernel (>= 6.19 < 6.19.7) • linux linux kernel 5.15 • linux linux kernel 7.0