filter: do not output bpf image address for security reason

Do not leak starting address of BPF JIT code for non root users,
as it might help intruders to perform an attack.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/filter.h b/include/linux/filter.h
index c050dcc..56a6b7f 100644 (file)
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -58,10 +58,10 @@ extern void bpf_jit_free(struct sk_filter *fp);
 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
                                u32 pass, void *image)
 {
-       pr_err("flen=%u proglen=%u pass=%u image=%p\n",
+       pr_err("flen=%u proglen=%u pass=%u image=%pK\n",
               flen, proglen, pass, image);
        if (image)
-               print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_ADDRESS,
+               print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
                               16, 1, image, proglen, false);
 }
 #define SK_RUN_FILTER(FILTER, SKB) (*FILTER->bpf_func)(SKB, FILTER->insns)