netfilter: fix ebtables compat support

commit 255d0dc34068a976 (netfilter: x_table: speedup compat operations)
made ebtables not working anymore.

1) xt_compat_calc_jump() is not an exact match lookup
2) compat_table_info() has a typo in xt_compat_init_offsets() call
3) compat_do_replace() misses a xt_compat_init_offsets() call

Reported-by: dann frazier <dannf@dannf.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

2 files changed, 4 insertions, 3 deletions

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 893669caa8de..9707079bc40a 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1766,7 +1766,7 @@ static int compat_table_info(const struct ebt_table_info *info,
 
         newinfo->entries_size = size;
 
-        xt_compat_init_offsets(AF_INET, info->nentries);
+        xt_compat_init_offsets(NFPROTO_BRIDGE, info->nentries);
         return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
                                                         entries, newinfo);
 }
@@ -2240,6 +2240,7 @@ static int compat_do_replace(struct net *net, void __user *user,
 
         xt_compat_lock(NFPROTO_BRIDGE);
 
+        xt_compat_init_offsets(NFPROTO_BRIDGE, tmp.nentries);
         ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
         if (ret < 0)
                 goto out_unlock;
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index a9adf4c6b299..8a025a585d2f 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -455,6 +455,7 @@ void xt_compat_flush_offsets(u_int8_t af)
                 vfree(xt[af].compat_tab);
                 xt[af].compat_tab = NULL;
                 xt[af].number = 0;
+                xt[af].cur = 0;
         }
 }
 EXPORT_SYMBOL_GPL(xt_compat_flush_offsets);
@@ -473,8 +474,7 @@ int xt_compat_calc_jump(u_int8_t af, unsigned int offset)
                 else
                         return mid ? tmp[mid - 1].delta : 0;
         }
-        WARN_ON_ONCE(1);
-        return 0;
+        return left ? tmp[left - 1].delta : 0;
 }
 EXPORT_SYMBOL_GPL(xt_compat_calc_jump);