[PATCH 5.4 044/100] perf bpf: Avoid memory leak from perf_env__insert_btf()

* [PATCH 5.4 044/100] perf bpf: Avoid memory leak from perf_env__insert_btf()
       [not found] <20211124115654.849735859@linuxfoundation.org>
@ 2021-11-24 11:58 ` Greg Kroah-Hartman
  2021-11-24 11:58 ` [PATCH 5.4 046/100] perf tests: Remove bash construct from record+zstd_comp_decomp.sh Greg Kroah-Hartman
  1 sibling, 0 replies; 2+ messages in thread
From: Greg Kroah-Hartman @ 2021-11-24 11:58 UTC (permalink / raw)
  To: linux-kernel
  Cc: Greg Kroah-Hartman, stable, Ian Rogers, Alexander Shishkin,
	Alexei Starovoitov, Andrii Nakryiko, Daniel Borkmann, Jiri Olsa,
	John Fastabend, KP Singh, Mark Rutland, Martin KaFai Lau,
	Namhyung Kim, Peter Zijlstra, Song Liu, Stephane Eranian,
	Tiezhu Yang, Yonghong Song, bpf, netdev,
	Arnaldo Carvalho de Melo, Sasha Levin

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 c766813d56be0..782c0c8a9a836 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -108,7 +108,11 @@ 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 0fafcf264d235..ef64e197bc8df 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -69,12 +69,13 @@ 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;
@@ -88,6 +89,7 @@ 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;
 		}
 	}
@@ -97,6 +99,7 @@ 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 db40906e29373..37028215d4a53 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -117,6 +117,6 @@ 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);
 #endif /* __PERF_ENV_H */
-- 
2.33.0




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