From 170a7e3ea0709eae12c8f944b9f33c54fe80c6c1 Mon Sep 17 00:00:00 2001 From: Sean Young Date: Sun, 27 May 2018 12:24:08 +0100 Subject: [PATCH] bpf: bpf_prog_array_copy() should return -ENOENT if exclude_prog not found This makes is it possible for bpf prog detach to return -ENOENT. Acked-by: Yonghong Song Signed-off-by: Sean Young Signed-off-by: Daniel Borkmann --- kernel/bpf/core.c | 11 +++++++++-- kernel/trace/bpf_trace.c | 2 ++ 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index b574dddc05b8..527587de8a67 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1616,6 +1616,7 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array, int new_prog_cnt, carry_prog_cnt = 0; struct bpf_prog **existing_prog; struct bpf_prog_array *array; + bool found_exclude = false; int new_prog_idx = 0; /* Figure out how many existing progs we need to carry over to @@ -1624,14 +1625,20 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array, if (old_array) { existing_prog = old_array->progs; for (; *existing_prog; existing_prog++) { - if (*existing_prog != exclude_prog && - *existing_prog != &dummy_bpf_prog.prog) + if (*existing_prog == exclude_prog) { + found_exclude = true; + continue; + } + if (*existing_prog != &dummy_bpf_prog.prog) carry_prog_cnt++; if (*existing_prog == include_prog) return -EEXIST; } } + if (exclude_prog && !found_exclude) + return -ENOENT; + /* How many progs (not NULL) will be in the new array? */ new_prog_cnt = carry_prog_cnt; if (include_prog) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 81fdf2fc94ac..af1486d9a0ed 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1006,6 +1006,8 @@ void perf_event_detach_bpf_prog(struct perf_event *event) old_array = event->tp_event->prog_array; ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array); + if (ret == -ENOENT) + goto unlock; if (ret < 0) { bpf_prog_array_delete_safe(old_array, event->prog); } else { -- 2.30.2