netfilter: xt_connmark: do not cast xt_connmark_tginfo1 to xt_connmark_tginfo2

These structures have different layout, fill xt_connmark_tginfo2 with
old fields in xt_connmark_tginfo1. Based on patch from Jack Ma.

Fixes: 472a73e00757 ("netfilter: xt_conntrack: Support bit-shifting for CONNMARK & MARK targets.")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/xt_connmark.c b/net/netfilter/xt_connmark.c
index 4b424e6caf3ec9da775d271b5445e5d4fe198d0f..94df000abb92d657addb2cad35028a2d3f08e024 100644 (file)
--- a/net/netfilter/xt_connmark.c
+++ b/net/netfilter/xt_connmark.c
@@ -36,9 +36,7 @@ MODULE_ALIAS("ipt_connmark");
 MODULE_ALIAS("ip6t_connmark");
 
 static unsigned int
-connmark_tg_shift(struct sk_buff *skb,
-               const struct xt_connmark_tginfo1 *info,
-               u8 shift_bits, u8 shift_dir)
+connmark_tg_shift(struct sk_buff *skb, const struct xt_connmark_tginfo2 *info)
 {
        enum ip_conntrack_info ctinfo;
        u_int32_t new_targetmark;
@@ -52,10 +50,11 @@ connmark_tg_shift(struct sk_buff *skb,
        switch (info->mode) {
        case XT_CONNMARK_SET:
                newmark = (ct->mark & ~info->ctmask) ^ info->ctmark;
-               if (shift_dir == D_SHIFT_RIGHT)
-                       newmark >>= shift_bits;
+               if (info->shift_dir == D_SHIFT_RIGHT)
+                       newmark >>= info->shift_bits;
                else
-                       newmark <<= shift_bits;
+                       newmark <<= info->shift_bits;
+
                if (ct->mark != newmark) {
                        ct->mark = newmark;
                        nf_conntrack_event_cache(IPCT_MARK, ct);
@@ -63,10 +62,11 @@ connmark_tg_shift(struct sk_buff *skb,
                break;
        case XT_CONNMARK_SAVE:
                new_targetmark = (skb->mark & info->nfmask);
-               if (shift_dir == D_SHIFT_RIGHT)
-                       new_targetmark >>= shift_bits;
+               if (info->shift_dir == D_SHIFT_RIGHT)
+                       new_targetmark >>= info->shift_bits;
                else
-                       new_targetmark <<= shift_bits;
+                       new_targetmark <<= info->shift_bits;
+
                newmark = (ct->mark & ~info->ctmask) ^
                          new_targetmark;
                if (ct->mark != newmark) {
@@ -76,10 +76,11 @@ connmark_tg_shift(struct sk_buff *skb,
                break;
        case XT_CONNMARK_RESTORE:
                new_targetmark = (ct->mark & info->ctmask);
-               if (shift_dir == D_SHIFT_RIGHT)
-                       new_targetmark >>= shift_bits;
+               if (info->shift_dir == D_SHIFT_RIGHT)
+                       new_targetmark >>= info->shift_bits;
                else
-                       new_targetmark <<= shift_bits;
+                       new_targetmark <<= info->shift_bits;
+
                newmark = (skb->mark & ~info->nfmask) ^
                          new_targetmark;
                skb->mark = newmark;
@@ -92,8 +93,14 @@ static unsigned int
 connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
 {
        const struct xt_connmark_tginfo1 *info = par->targinfo;
-
-       return connmark_tg_shift(skb, info, 0, 0);
+       const struct xt_connmark_tginfo2 info2 = {
+               .ctmark = info->ctmark,
+               .ctmask = info->ctmask,
+               .nfmask = info->nfmask,
+               .mode   = info->mode,
+       };
+
+       return connmark_tg_shift(skb, &info2);
 }
 
 static unsigned int
@@ -101,8 +108,7 @@ connmark_tg_v2(struct sk_buff *skb, const struct xt_action_param *par)
 {
        const struct xt_connmark_tginfo2 *info = par->targinfo;
 
-       return connmark_tg_shift(skb, (const struct xt_connmark_tginfo1 *)info,
-                                info->shift_bits, info->shift_dir);
+       return connmark_tg_shift(skb, info);
 }
 
 static int connmark_tg_check(const struct xt_tgchk_param *par)