tools: bpftool: fix crash with un-owned prog arrays
Prog arrays don't have 'owner_prog_type' and 'owner_jited'
fields in their fdinfo when they are created. Those fields
are set and reported when first program is checked for
compatibility by bpf_prog_array_compatible().
This means that bpftool cannot expect the fields to always
be there. Currently trying to show maps on a system with
an un-owned prog array leads to a crash:
$ bpftool map show
389: prog_array name tail_call_map flags 0x0
Error: key 'owner_prog_type' not found in fdinfo
Error: key 'owner_jited' not found in fdinfo
key 4B value 4B max_entries 4 memlock 4096B
Segmentation fault (core dumped)
We pass a NULL pointer to atoi().
Remove the assumption that fdinfo keys are always present.
Add missing validations and remove the p_err() calls which
may lead to broken JSON output as caller will not propagate
the failure.
Fixes: 99a44bef5870 ("tools: bpftool: add owner_prog_type and owner_jited to bpftool output")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index 8974834..f7261fa 100644
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -297,10 +297,8 @@ char *get_fdinfo(int fd, const char *key)
snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", fd);
fdi = fopen(path, "r");
- if (!fdi) {
- p_err("can't open fdinfo: %s", strerror(errno));
+ if (!fdi)
return NULL;
- }
while ((n = getline(&line, &line_n, fdi)) > 0) {
char *value;
@@ -313,7 +311,6 @@ char *get_fdinfo(int fd, const char *key)
value = strchr(line, '\t');
if (!value || !value[1]) {
- p_err("malformed fdinfo!?");
free(line);
return NULL;
}
@@ -326,7 +323,6 @@ char *get_fdinfo(int fd, const char *key)
return line;
}
- p_err("key '%s' not found in fdinfo", key);
free(line);
fclose(fdi);
return NULL;
