korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-09-21 20:22:13 +08:00
Code Issues Packages Projects Releases Wiki Activity

bpftool: Avoid leaking the JSON writer prepared for program metadata

Browse Source 
Bpftool creates a new JSON object for writing program metadata in plain
text mode, regardless of metadata being present or not. Then this writer
is freed if any metadata has been found and printed, but it leaks
otherwise. We cannot destroy the object unconditionally, because the
destructor prints an undesirable line break. Instead, make sure the
writer is created only after we have found program metadata to print.

Found with valgrind.

Fixes: aff52e685e ("bpftool: Support dumping metadata")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211022094743.11052-1-quentin@isovalent.com
This commit is contained in:
Quentin Monnet 2021-10-22 10:47:43 +01:00 committed by Andrii Nakryiko
parent 59f2a29c04
commit e89ef634f8
1 changed files with 9 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
tools/bpf/bpftool/prog.c
View File

@ -307,18 +307,12 @@ static void show_prog_metadata(int fd, __u32 num_maps)
if (printed_header)
jsonw_end_object(json_wtr);
} else {
json_writer_t *btf_wtr = jsonw_new(stdout);
json_writer_t *btf_wtr;
struct btf_dumper d = {
.btf = btf,
.jw = btf_wtr,
.is_plain_text = true,
};
if (!btf_wtr) {
p_err("jsonw alloc failed");
goto out_free;
}
for (i = 0; i < vlen; i++, vsi++) {
t_var = btf__type_by_id(btf, vsi->type);
name = btf__name_by_offset(btf, t_var->name_off);
@ -328,6 +322,14 @@ static void show_prog_metadata(int fd, __u32 num_maps)
if (!printed_header) {
printf("\tmetadata:");
btf_wtr = jsonw_new(stdout);
if (!btf_wtr) {
p_err("jsonw alloc failed");
goto out_free;
}
d.jw = btf_wtr,
printed_header = true;
}