[PATCH 6.1 0208/1146] selftest/bpf: Fix memory leak in kprobe_multi_test

Greg Kroah-Hartman
2022-12-28T15:25:27Z

From: Xu Kuohai <xukuohai@huawei.com>

[ Upstream commit 6d2e21dc4db3933db65293552ecc1ede26febeca ]

The get_syms() function in kprobe_multi_test.c does not free the string
memory allocated by sscanf correctly. Fix it.

Fixes: 5b6c7e5c4434 ("selftests/bpf: Add attach bench test")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/bpf/20221011120108.782373-5-xukuohai@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../bpf/prog_tests/kprobe_multi_test.c | 26 ++++++++++---------
1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
index a4b4133d39e9..0d82e28aed1a 100644
--- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c
@@ -325,7 +325,7 @@ static bool symbol_equal(const void *key1, const void *key2, void *ctx __maybe_u
static int get_syms(char ***symsp, size_t *cntp)
{
size_t cap = 0, cnt = 0, i;
- char *name, **syms = NULL;
+ char *name = NULL, **syms = NULL;
struct hashmap *map;
char buf[256];
FILE *f;
@@ -352,6 +352,8 @@ static int get_syms(char ***symsp, size_t *cntp)
/* skip modules */
if (strchr(buf, '['))
continue;
+
+ free(name);
if (sscanf(buf, "%ms$*[^\n]\n", &name) != 1)
continue;
/*
@@ -371,32 +373,32 @@ static int get_syms(char ***symsp, size_t *cntp)
if (!strncmp(name, "__ftrace_invalid_address__",
sizeof("__ftrace_invalid_address__") - 1))
continue;
+
err = hashmap__add(map, name, NULL);
- if (err) {
- free(name);
- if (err == -EEXIST)
- continue;
+ if (err == -EEXIST)
+ continue;
+ if (err)
goto error;
- }
+
err = libbpf_ensure_mem((void **) &syms, &cap,
sizeof(*syms), cnt + 1);
- if (err) {
- free(name);
+ if (err)
goto error;
- }
- syms[cnt] = name;
- cnt++;
+
+ syms[cnt++] = name;
+ name = NULL;
}

*symsp = syms;
*cntp = cnt;

error:
+ free(name);
fclose(f);
hashmap__free(map);
if (err) {
for (i = 0; i < cnt; i++)
- free(syms[cnt]);
+ free(syms[i]);
free(syms);
}
return err;
--
2.35.1