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| author | Quentin Monnet <quentin.monnet@netronome.com> | 2017-11-29 02:44:28 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2017-11-30 02:09:29 +0100 |
| commit | 9b85c2d4508563f4bb1de0d971ed02fea0d0d757 (patch) | |
| tree | e9d2683c58114c5b9c78a058d881c117bf1fd75d /tools/bpf/bpftool/main.c | |
| parent | bpf: offload: add a license header (diff) | |
| download | linux-9b85c2d4508563f4bb1de0d971ed02fea0d0d757.tar.xz linux-9b85c2d4508563f4bb1de0d971ed02fea0d0d757.zip | |
tools: bpftool: fix crash on bad parameters with JSON
If bad or unrecognised parameters are specified after JSON output is
requested, `usage()` will try to output null JSON object before the
writer is created.
To prevent this, create the writer as soon as the `--json` option is
parsed.
Fixes: 004b45c0e51a ("tools: bpftool: provide JSON output for all possible commands")
Reported-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'tools/bpf/bpftool/main.c')
| -rw-r--r-- | tools/bpf/bpftool/main.c | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c index d6e4762170a4..14ad54a1c404 100644 --- a/tools/bpf/bpftool/main.c +++ b/tools/bpf/bpftool/main.c @@ -291,7 +291,15 @@ int main(int argc, char **argv) pretty_output = true; /* fall through */ case 'j': - json_output = true; + if (!json_output) { + json_wtr = jsonw_new(stdout); + if (!json_wtr) { + p_err("failed to create JSON writer"); + return -1; + } + json_output = true; + } + jsonw_pretty(json_wtr, pretty_output); break; case 'f': show_pinned = true; @@ -306,15 +314,6 @@ int main(int argc, char **argv) if (argc < 0) usage(); - if (json_output) { - json_wtr = jsonw_new(stdout); - if (!json_wtr) { - p_err("failed to create JSON writer"); - return -1; - } - jsonw_pretty(json_wtr, pretty_output); - } - bfd_init(); ret = cmd_select(cmds, argc, argv, do_help); |