From 89fcbb564f4a64c439d597c2702f990eed49c8a1 Mon Sep 17 00:00:00 2001 From: Subash Abhinov Kasiviswanathan Date: Thu, 21 Sep 2017 19:01:36 -0600 Subject: [PATCH] netfilter: xt_socket: Restore mark from full sockets only An out of bounds error was detected on an ARM64 target with Android based kernel 4.9. This occurs while trying to restore mark on a skb from an inet request socket. BUG: KASAN: slab-out-of-bounds in socket_match.isra.2+0xc8/0x1f0 net/netfilter/xt_socket.c:248 Read of size 4 at addr ffffffc06a8d824c by task syz-fuzzer/1532 CPU: 7 PID: 1532 Comm: syz-fuzzer Tainted: G W O 4.9.41+ #1 Call trace: [] dump_backtrace+0x0/0x440 arch/arm64/kernel/traps.c:76 [] show_stack+0x28/0x38 arch/arm64/kernel/traps.c:226 [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xe4/0x134 lib/dump_stack.c:51 [] print_address_description+0x68/0x258 mm/kasan/report.c:248 [] kasan_report_error mm/kasan/report.c:347 [inline] [] kasan_report.part.2+0x228/0x2f0 mm/kasan/report.c:371 [] kasan_report+0x5c/0x70 mm/kasan/report.c:372 [] check_memory_region_inline mm/kasan/kasan.c:308 [inline] [] __asan_load4+0x88/0xa0 mm/kasan/kasan.c:740 [] socket_match.isra.2+0xc8/0x1f0 net/netfilter/xt_socket.c:248 [] socket_mt4_v1_v2_v3+0x3c/0x48 net/netfilter/xt_socket.c:272 [] ipt_do_table+0x54c/0xad8 net/ipv4/netfilter/ip_tables.c:311 [] iptable_mangle_hook+0x6c/0x220 net/ipv4/netfilter/iptable_mangle.c:90 ... Allocated by task 1532: save_stack_trace_tsk+0x0/0x2a0 arch/arm64/kernel/stacktrace.c:131 save_stack_trace+0x28/0x38 arch/arm64/kernel/stacktrace.c:215 save_stack mm/kasan/kasan.c:495 [inline] set_track mm/kasan/kasan.c:507 [inline] kasan_kmalloc+0xd8/0x188 mm/kasan/kasan.c:599 kasan_slab_alloc+0x14/0x20 mm/kasan/kasan.c:537 slab_post_alloc_hook mm/slab.h:417 [inline] slab_alloc_node mm/slub.c:2728 [inline] slab_alloc mm/slub.c:2736 [inline] kmem_cache_alloc+0x14c/0x2e8 mm/slub.c:2741 reqsk_alloc include/net/request_sock.h:87 [inline] inet_reqsk_alloc+0x4c/0x238 net/ipv4/tcp_input.c:6236 tcp_conn_request+0x2b0/0xea8 net/ipv4/tcp_input.c:6341 tcp_v4_conn_request+0xe0/0x100 net/ipv4/tcp_ipv4.c:1256 tcp_rcv_state_process+0x384/0x18a8 net/ipv4/tcp_input.c:5926 tcp_v4_do_rcv+0x2f0/0x3e0 net/ipv4/tcp_ipv4.c:1430 tcp_v4_rcv+0x1278/0x1350 net/ipv4/tcp_ipv4.c:1709 ip_local_deliver_finish+0x174/0x3e0 net/ipv4/ip_input.c:216 v1->v2: Change socket_mt6_v1_v2_v3() as well as mentioned by Eric v2->v3: Put the correct fixes tag Fixes: 01555e74bde5 ("netfilter: xt_socket: add XT_SOCKET_RESTORESKMARK flag") Signed-off-by: Subash Abhinov Kasiviswanathan Signed-off-by: Pablo Neira Ayuso --- net/netfilter/xt_socket.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c index e75ef39669c5..575d2153e3b8 100644 --- a/net/netfilter/xt_socket.c +++ b/net/netfilter/xt_socket.c @@ -76,7 +76,7 @@ socket_match(const struct sk_buff *skb, struct xt_action_param *par, transparent = nf_sk_is_transparent(sk); if (info->flags & XT_SOCKET_RESTORESKMARK && !wildcard && - transparent) + transparent && sk_fullsock(sk)) pskb->mark = sk->sk_mark; if (sk != skb->sk) @@ -133,7 +133,7 @@ socket_mt6_v1_v2_v3(const struct sk_buff *skb, struct xt_action_param *par) transparent = nf_sk_is_transparent(sk); if (info->flags & XT_SOCKET_RESTORESKMARK && !wildcard && - transparent) + transparent && sk_fullsock(sk)) pskb->mark = sk->sk_mark; if (sk != skb->sk)