From: Arnaldo Carvalho de Melo acme@redhat.com
commit 31ded1535e3182778a1d0e5c32711f55da3bc512 upstream.
This was detected by the gcc in Fedora Rawhide's gcc:
50 11.01 fedora:rawhide : FAIL gcc version 12.0.1 20220205 (Red Hat 12.0.1-0) (GCC) inlined from 'bpf__config_obj' at util/bpf-loader.c:1242:9: util/bpf-loader.c:1225:34: error: pointer 'map_opt' may be used after 'free' [-Werror=use-after-free] 1225 | *key_scan_pos += strlen(map_opt); | ^~~~~~~~~~~~~~~ util/bpf-loader.c:1223:9: note: call to 'free' here 1223 | free(map_name); | ^~~~~~~~~~~~~~ cc1: all warnings being treated as errors
So do the calculations on the pointer before freeing it.
Fixes: 04f9bf2bac72480c ("perf bpf-loader: Add missing '*' for key_scan_pos") Cc: Adrian Hunter adrian.hunter@intel.com Cc: Ian Rogers irogers@google.com Cc: Jiri Olsa jolsa@kernel.org Cc: Namhyung Kim namhyung@kernel.org Cc: Wang ShaoBo bobo.shaobowang@huawei.com Link: https://lore.kernel.org/lkml/Yg1VtQxKrPpS3uNA@kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/perf/util/bpf-loader.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/tools/perf/util/bpf-loader.c +++ b/tools/perf/util/bpf-loader.c @@ -1214,9 +1214,10 @@ bpf__obj_config_map(struct bpf_object *o pr_debug("ERROR: Invalid map config option '%s'\n", map_opt); err = -BPF_LOADER_ERRNO__OBJCONF_MAP_OPT; out: - free(map_name); if (!err) *key_scan_pos += strlen(map_opt); + + free(map_name); return err; }