1 files changed, 16 insertions, 13 deletions

diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 3c35ced39b42..0771991ed812 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -305,7 +305,7 @@ static void trace_packet(const struct sk_buff *skb,
 }
 #endif
 
-static inline __pure struct ip6t_entry *
+static inline struct ip6t_entry *
 ip6t_next_entry(const struct ip6t_entry *entry)
 {
 	return (void *)entry + entry->next_offset;
@@ -324,12 +324,13 @@ ip6t_do_table(struct sk_buff *skb,
 	const char *indev, *outdev;
 	const void *table_base;
 	struct ip6t_entry *e, **jumpstack;
-	unsigned int *stackptr, origptr, cpu;
+	unsigned int stackidx, cpu;
 	const struct xt_table_info *private;
 	struct xt_action_param acpar;
 	unsigned int addend;
 
 	/* Initialization */
+	stackidx = 0;
 	indev = state->in ? state->in->name : nulldevname;
 	outdev = state->out ? state->out->name : nulldevname;
 	/* We handle fragments by dealing with the first fragment as
@@ -357,8 +358,16 @@ ip6t_do_table(struct sk_buff *skb,
 	cpu        = smp_processor_id();
 	table_base = private->entries;
 	jumpstack  = (struct ip6t_entry **)private->jumpstack[cpu];
-	stackptr   = per_cpu_ptr(private->stackptr, cpu);
-	origptr    = *stackptr;
+
+	/* Switch to alternate jumpstack if we're being invoked via TEE.
+	 * TEE issues XT_CONTINUE verdict on original skb so we must not
+	 * clobber the jumpstack.
+	 *
+	 * For recursion via REJECT or SYNPROXY the stack will be clobbered
+	 * but it is no problem since absolute verdict is issued by these.
+	 */
+	if (static_key_false(&xt_tee_enabled))
+		jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated);
 
 	e = get_entry(table_base, private->hook_entry[hook]);
 
@@ -406,20 +415,16 @@ ip6t_do_table(struct sk_buff *skb,
 					verdict = (unsigned int)(-v) - 1;
 					break;
 				}
-				if (*stackptr <= origptr)
+				if (stackidx == 0)
 					e = get_entry(table_base,
 					    private->underflow[hook]);
 				else
-					e = ip6t_next_entry(jumpstack[--*stackptr]);
+					e = ip6t_next_entry(jumpstack[--stackidx]);
 				continue;
 			}
 			if (table_base + v != ip6t_next_entry(e) &&
 			    !(e->ipv6.flags & IP6T_F_GOTO)) {
-				if (*stackptr >= private->stacksize) {
-					verdict = NF_DROP;
-					break;
-				}
-				jumpstack[(*stackptr)++] = e;
+				jumpstack[stackidx++] = e;
 			}
 
 			e = get_entry(table_base, v);
@@ -437,8 +442,6 @@ ip6t_do_table(struct sk_buff *skb,
 			break;
 	} while (!acpar.hotdrop);
 
-	*stackptr = origptr;
-
  	xt_write_recseq_end(addend);
  	local_bh_enable();