[PATCH] perf env: fix memory leak: free bpf_prog_info_linear

From: Riccardo Mancini
Date: Wed Jun 02 2021 - 18:41:41 EST


ASan reported a memory leak caused by info_linear not being
deallocated. The info_linear was allocated during
perf_event__synthesize_one_bpf_prog.
This patch adds the corresponding free() when bpf_prog_info_node
is freed in perf_env__purge_bpf.

$ sudo ./perf record -- sleep 5
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.025 MB perf.data (8 samples) ]

=================================================================
==297735==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 7688 byte(s) in 19 object(s) allocated from:
#0 0x4f420f in malloc (/home/user/linux/tools/perf/perf+0x4f420f)
#1 0xc06a74 in bpf_program__get_prog_info_linear /home/user/linux/tools/lib/bpf/libbpf.c:11113:16
#2 0xb426fe in perf_event__synthesize_one_bpf_prog /home/user/linux/tools/perf/util/bpf-event.c:191:16
#3 0xb42008 in perf_event__synthesize_bpf_events /home/user/linux/tools/perf/util/bpf-event.c:410:9
#4 0x594596 in record__synthesize /home/user/linux/tools/perf/builtin-record.c:1490:8
#5 0x58c9ac in __cmd_record /home/user/linux/tools/perf/builtin-record.c:1798:8
#6 0x58990b in cmd_record /home/user/linux/tools/perf/builtin-record.c:2901:8
#7 0x7b2a20 in run_builtin /home/user/linux/tools/perf/perf.c:313:11
#8 0x7b12ff in handle_internal_command /home/user/linux/tools/perf/perf.c:365:8
#9 0x7b2583 in run_argv /home/user/linux/tools/perf/perf.c:409:2
#10 0x7b0d79 in main /home/user/linux/tools/perf/perf.c:539:3
#11 0x7fa357ef6b74 in __libc_start_main /usr/src/debug/glibc-2.33-8.fc34.x86_64/csu/../csu/libc-start.c:332:16

Signed-off-by: Riccardo Mancini <rickyman7@xxxxxxxxx>
---
tools/perf/util/env.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index 9130f6fad8d54..bc5e4f294e9e9 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -144,6 +144,7 @@ static void perf_env__purge_bpf(struct perf_env *env)
node = rb_entry(next, struct bpf_prog_info_node, rb_node);
next = rb_next(&node->rb_node);
rb_erase(&node->rb_node, root);
+ free(node->info_linear);
free(node);
}

--
2.31.1