From 87ee6de0d824e9051950b8b812a816d209f054a1 Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Thu, 11 Nov 2021 23:45:25 -0800 Subject: [PATCH] perf bpf: Avoid memory leak from perf_env__insert_btf() perf_env__insert_btf() doesn't insert if a duplicate BTF id is encountered and this causes a memory leak. Modify the function to return a success/error value and then free the memory if insertion didn't happen. v2. Adds a return -1 when the insertion error occurs in perf_env__fetch_btf. This doesn't affect anything as the result is never checked. Fixes: a7bc1ef9833afc34 ("perf bpf: Save BTF in a rbtree in perf_env") Signed-off-by: Ian Rogers Cc: Alexander Shishkin Cc: Alexei Starovoitov Cc: Andrii Nakryiko Cc: Daniel Borkmann Cc: Jiri Olsa Cc: John Fastabend Cc: KP Singh Cc: Mark Rutland Cc: Martin KaFai Lau Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Song Liu Cc: Stephane Eranian Cc: Tiezhu Yang Cc: Yonghong Song Cc: bpf@vger.kernel.org Cc: netdev@vger.kernel.org Link: http://lore.kernel.org/lkml/20211112074525.121633-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/bpf-event.c | 6 +++++- tools/perf/util/env.c | 5 ++++- tools/perf/util/env.h | 2 +- 3 files changed, 10 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c index 4d3b4cdce1763..d49cdff8fb395 100644 --- a/tools/perf/util/bpf-event.c +++ b/tools/perf/util/bpf-event.c @@ -119,7 +119,11 @@ static int perf_env__fetch_btf(struct perf_env *env, node->data_size = data_size; memcpy(node->data, data, data_size); - perf_env__insert_btf(env, node); + if (!perf_env__insert_btf(env, node)) { + /* Insertion failed because of a duplicate. */ + free(node); + return -1; + } return 0; } diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c index 17f1dd0680b42..b9904896eb974 100644 --- a/tools/perf/util/env.c +++ b/tools/perf/util/env.c @@ -75,12 +75,13 @@ out: return node; } -void perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node) +bool perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node) { struct rb_node *parent = NULL; __u32 btf_id = btf_node->id; struct btf_node *node; struct rb_node **p; + bool ret = true; down_write(&env->bpf_progs.lock); p = &env->bpf_progs.btfs.rb_node; @@ -94,6 +95,7 @@ void perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node) p = &(*p)->rb_right; } else { pr_debug("duplicated btf %u\n", btf_id); + ret = false; goto out; } } @@ -103,6 +105,7 @@ void perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node) env->bpf_progs.btfs_cnt++; out: up_write(&env->bpf_progs.lock); + return ret; } struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id) diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h index 1383876f72b37..163e5ec503a26 100644 --- a/tools/perf/util/env.h +++ b/tools/perf/util/env.h @@ -167,7 +167,7 @@ void perf_env__insert_bpf_prog_info(struct perf_env *env, struct bpf_prog_info_node *info_node); struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env, __u32 prog_id); -void perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node); +bool perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node); struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id); int perf_env__numa_node(struct perf_env *env, int cpu); -- 2.39.5