In the Linux kernel, the following vulnerability has been resolved: net: shaper: reject duplicate leaves in GROUP request net_shaper_nl_group_doit() does not deduplicate NET_SHAPER_A_LEAVES entries. When userspace supplies the same leaf handle twice, the same old-parent pointer lands twice in old_nodes[]. The cleanup loop double frees the parent. Of course the same parent may still be in old_nodes[] twice if we are moving multiple of its leaves. Note that this patch also implicitly fixes the fact that the i >= leaves_count path forgets to set ret.
https://git.kernel.org/stable/c/a9a2fa1da619f276580b0d4c5d12efac89e8642b
https://git.kernel.org/stable/c/5098b223f0f0c5c18a3884a8b0ea5bd4a0c7bd75
https://git.kernel.org/stable/c/31767bf852b59f05125b58a17007e4cd1ea9eb2e