netfilter: x_tables: make sure compat af mutex is held

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 33724b08b8f0366ec0cde15eb829614dbe74ae85..7521e8a72c064ed3196560c8bfbb9c1340380a68 100644 (file)
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -582,6 +582,8 @@ int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta)
 {
        struct xt_af *xp = &xt[af];
 
+       WARN_ON(!mutex_is_locked(&xt[af].compat_mutex));
+
        if (WARN_ON(!xp->compat_tab))
                return -ENOMEM;
 
@@ -599,6 +601,8 @@ EXPORT_SYMBOL_GPL(xt_compat_add_offset);
 
 void xt_compat_flush_offsets(u_int8_t af)
 {
+       WARN_ON(!mutex_is_locked(&xt[af].compat_mutex));
+
        if (xt[af].compat_tab) {
                vfree(xt[af].compat_tab);
                xt[af].compat_tab = NULL;
@@ -630,6 +634,8 @@ int xt_compat_init_offsets(u8 af, unsigned int number)
 {
        size_t mem;
 
+       WARN_ON(!mutex_is_locked(&xt[af].compat_mutex));
+
        if (!number || number > (INT_MAX / sizeof(struct compat_delta)))
                return -EINVAL;