[PATCH v2 2/4] perf tools: Fix double free and memory leak in kvm_events_record()
Michalis Niarchos <[email protected]> Mon, 03 Aug 2026 15:05:41 +0200
| Newsgroups | org.kernel.feeds.b4-sent,org.kernel.vger.linux-kernel,org.kernel.vger.linux-perf-users |
|---|---|
| Message-ID | <[email protected]> |
cmd_record() reorders the contents of the rec_argv pointer array, so its entry order no longer matches the order in which the caller originally allocated them. Freeing the contents of rec_argv by iterating the reordered array results in some pointers being freed twice and others never freed. All the entries of rec_argv come from literals or pointers that are valid for the lifetime of this call. Reference them directly instead of duplicating to remove the need to individually track and free each entry. Signed-off-by: Michalis Niarchos <[email protected]> --- tools/perf/builtin-kvm.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c index 44c6998f2ee5..45c92ab74fdd 100644 --- a/tools/perf/builtin-kvm.c +++ b/tools/perf/builtin-kvm.c @@ -1681,18 +1681,18 @@ kvm_events_record(struct perf_kvm_stat *kvm, int argc, const char **argv) return -ENOMEM; for (i = 0; i < ARRAY_SIZE(record_args); i++) - rec_argv[i] = STRDUP_FAIL_EXIT(record_args[i]); + rec_argv[i] = record_args[i]; for (j = 0; j < events_tp_size; j++) { - rec_argv[i++] = STRDUP_FAIL_EXIT("-e"); - rec_argv[i++] = STRDUP_FAIL_EXIT(kvm_events_tp(e_machine)[j]); + rec_argv[i++] = "-e"; + rec_argv[i++] = kvm_events_tp(e_machine)[j]; } - rec_argv[i++] = STRDUP_FAIL_EXIT("-o"); - rec_argv[i++] = STRDUP_FAIL_EXIT(kvm->file_name); + rec_argv[i++] = "-o"; + rec_argv[i++] = kvm->file_name; for (j = 1; j < (unsigned int)argc; j++, i++) - rec_argv[i] = STRDUP_FAIL_EXIT(argv[j]); + rec_argv[i] = argv[j]; set_option_flag(record_options, 'e', "event", PARSE_OPT_HIDDEN); set_option_flag(record_options, 0, "filter", PARSE_OPT_HIDDEN); @@ -1717,9 +1717,6 @@ kvm_events_record(struct perf_kvm_stat *kvm, int argc, const char **argv) record_usage = kvm_stat_record_usage; ret = cmd_record(i, rec_argv); -EXIT: - for (i = 0; i < rec_argc; i++) - free((void *)rec_argv[i]); free(rec_argv); return ret; } -- 2.55.0