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>

1 files changed, 22 insertions, 16 deletions

diff --git a/net/netfilter/xt_connmark.c b/net/netfilter/xt_connmark.c
index 4b424e6caf3e..94df000abb92 100644
--- 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)