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

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 <redacted>
---
 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

On Wed, Jun 2, 2021 at 3:41 PM Riccardo Mancini [off-list ref] wrote:

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 <redacted>

Acked-by: Ian Rogers <irogers@google.com>

Thanks,
Ian

Em Thu, Jun 03, 2021 at 09:15:32PM -0700, Ian Rogers escreveu:

On Wed, Jun 2, 2021 at 3:41 PM Riccardo Mancini [off-list ref] wrote:

quoted

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 <redacted>

Acked-by: Ian Rogers <irogers@google.com>

Thanks, applied.

- Arnaldo