This is a note to let you know that I've just added the patch titled perf bpf: Avoid memory leak from perf_env__insert_btf() to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: perf-bpf-avoid-memory-leak-from-perf_env__insert_btf.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit d2be9165e217322dcce0241a726bd2d59be460d9 Author: Ian Rogers <irogers@xxxxxxxxxx> Date: Thu Nov 11 23:45:25 2021 -0800 perf bpf: Avoid memory leak from perf_env__insert_btf() [ 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@xxxxxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Alexei Starovoitov <ast@xxxxxxxxxx> Cc: Andrii Nakryiko <andrii@xxxxxxxxxx> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: John Fastabend <john.fastabend@xxxxxxxxx> Cc: KP Singh <kpsingh@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Martin KaFai Lau <kafai@xxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Song Liu <songliubraving@xxxxxx> Cc: Stephane Eranian <eranian@xxxxxxxxxx> Cc: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> Cc: Yonghong Song <yhs@xxxxxx> Cc: bpf@xxxxxxxxxxxxxxx Cc: netdev@xxxxxxxxxxxxxxx Link: http://lore.kernel.org/lkml/20211112074525.121633-1-irogers@xxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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 @@ struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env, 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 */