tools: bpf_jit_disasm: check for klogctl failure

klogctl can fail and return -ve len, so check for this and
return NULL to avoid passing a (size_t)-1 to malloc.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/tools/net/bpf_jit_disasm.c b/tools/net/bpf_jit_disasm.c
index 5b32413409459ce165e2f56990dbc0f52aa8bd31..544b05a53b7057bbe9092e31f600065d47e3b24e 100644 (file)
--- a/tools/net/bpf_jit_disasm.c
+++ b/tools/net/bpf_jit_disasm.c
@@ -98,6 +98,9 @@ static char *get_klog_buff(unsigned int *klen)
        char *buff;
 
        len = klogctl(CMD_ACTION_SIZE_BUFFER, NULL, 0);
+       if (len < 0)
+               return NULL;
+
        buff = malloc(len);
        if (!buff)
                return NULL;