diff mbox series

[v1,nf,2/2] netfilter: iptables: Fix potential null-ptr-deref in ip6table_nat_table_init().

Message ID 20240725192822.4478-3-kuniyu@amazon.com (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series netfilter: iptables: Fix null-ptr-deref in ip6?table_nat_table_init(). | expand

Checks

Context Check Description
netdev/series_format warning Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 273 this patch: 273
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 4 maintainers not CCed: edumazet@google.com dsahern@kernel.org pabeni@redhat.com kuba@kernel.org
netdev/build_clang success Errors and warnings before: 281 this patch: 281
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 281 this patch: 281
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 32 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest fail net-next-2024-07-25--21-00 (tests: 702)

Commit Message

Kuniyuki Iwashima July 25, 2024, 7:28 p.m. UTC 
ip6table_nat_table_init() accesses net->gen->ptr[ip6table_nat_net_ops.id],
but the function is exposed to user space before the entry is allocated
via register_pernet_subsys().

Let's call register_pernet_subsys() before xt_register_template().

Fixes: fdacd57c79b7 ("netfilter: x_tables: never register tables by default")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 net/ipv6/netfilter/ip6table_nat.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv6/netfilter/ip6table_nat.c b/net/ipv6/netfilter/ip6table_nat.c
index 52cf104e3478..e119d4f090cc 100644
--- a/net/ipv6/netfilter/ip6table_nat.c
+++ b/net/ipv6/netfilter/ip6table_nat.c
@@ -147,23 +147,27 @@  static struct pernet_operations ip6table_nat_net_ops = {
 
 static int __init ip6table_nat_init(void)
 {
-	int ret = xt_register_template(&nf_nat_ipv6_table,
-				       ip6table_nat_table_init);
+	int ret;
 
+	/* net->gen->ptr[ip6table_nat_net_id] must be allocated
+	 * before calling ip6t_nat_register_lookups().
+	 */
+	ret = register_pernet_subsys(&ip6table_nat_net_ops);
 	if (ret < 0)
 		return ret;
 
-	ret = register_pernet_subsys(&ip6table_nat_net_ops);
+	ret = xt_register_template(&nf_nat_ipv6_table,
+				   ip6table_nat_table_init);
 	if (ret)
-		xt_unregister_template(&nf_nat_ipv6_table);
+		unregister_pernet_subsys(&ip6table_nat_net_ops);
 
 	return ret;
 }
 
 static void __exit ip6table_nat_exit(void)
 {
-	unregister_pernet_subsys(&ip6table_nat_net_ops);
 	xt_unregister_template(&nf_nat_ipv6_table);
+	unregister_pernet_subsys(&ip6table_nat_net_ops);
 }
 
 module_init(ip6table_nat_init);