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Subject[PATCH 5.10 065/154] perf bpf: Avoid memory leak from perf_env__insert_btf()
Date
From: Ian Rogers <irogers@google.com>

[ Upstream commit 4924b1f7c46711762fd0e65c135ccfbcfd6ded1f ]

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: 3792cb2ff43b1b19 ("perf bpf: Save BTF in a rbtree in perf_env")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Yonghong Song <yhs@fb.com>
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 <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 c8101575dbf45..4eb02762104ba 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -109,7 +109,11 @@ 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 f0dceb527ca38..d81ed1bc14bdc 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -71,12 +71,13 @@ 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;
@@ -90,6 +91,7 @@ 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;
}
}
@@ -99,6 +101,7 @@ 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 a129726520064..01378a955dd5e 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -143,7 +143,7 @@ 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);
--
2.33.0


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