[PATCH 3.16 149/366] netfilter: nf_queue: augment nfqa_cfg_policy

Ben Hutchings
2018-11-11T19:49:05Z

From: Eric Dumazet <edumazet@google.com>

commit ba062ebb2cd561d404e0fba8ee4b3f5ebce7cbfc upstream.

Three attributes are currently not verified, thus can trigger KMSAN
warnings such as :

BUG: KMSAN: uninit-value in __arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline]
BUG: KMSAN: uninit-value in __fswab32 include/uapi/linux/swab.h:59 [inline]
BUG: KMSAN: uninit-value in nfqnl_recv_config+0x939/0x17d0 net/netfilter/nfnetlink_queue.c:1268
CPU: 1 PID: 4521 Comm: syz-executor120 Not tainted 4.17.0+ #5
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x185/0x1d0 lib/dump_stack.c:113
kmsan_report+0x188/0x2a0 mm/kmsan/kmsan.c:1117
__msan_warning_32+0x70/0xc0 mm/kmsan/kmsan_instr.c:620
__arch_swab32 arch/x86/include/uapi/asm/swab.h:10 [inline]
__fswab32 include/uapi/linux/swab.h:59 [inline]
nfqnl_recv_config+0x939/0x17d0 net/netfilter/nfnetlink_queue.c:1268
nfnetlink_rcv_msg+0xb2e/0xc80 net/netfilter/nfnetlink.c:212
netlink_rcv_skb+0x37e/0x600 net/netlink/af_netlink.c:2448
nfnetlink_rcv+0x2fe/0x680 net/netfilter/nfnetlink.c:513
netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
netlink_unicast+0x1680/0x1750 net/netlink/af_netlink.c:1336
netlink_sendmsg+0x104f/0x1350 net/netlink/af_netlink.c:1901
sock_sendmsg_nosec net/socket.c:629 [inline]
sock_sendmsg net/socket.c:639 [inline]
___sys_sendmsg+0xec8/0x1320 net/socket.c:2117
__sys_sendmsg net/socket.c:2155 [inline]
__do_sys_sendmsg net/socket.c:2164 [inline]
__se_sys_sendmsg net/socket.c:2162 [inline]
__x64_sys_sendmsg+0x331/0x460 net/socket.c:2162
do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x43fd59
RSP: 002b:00007ffde0e30d28 EFLAGS: 00000213 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fd59
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000213 R12: 0000000000401680
R13: 0000000000401710 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:189
kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:315
kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan.c:322
slab_post_alloc_hook mm/slab.h:446 [inline]
slab_alloc_node mm/slub.c:2753 [inline]
__kmalloc_node_track_caller+0xb35/0x11b0 mm/slub.c:4395
__kmalloc_reserve net/core/skbuff.c:138 [inline]
__alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206
alloc_skb include/linux/skbuff.h:988 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline]
netlink_sendmsg+0x76e/0x1350 net/netlink/af_netlink.c:1876
sock_sendmsg_nosec net/socket.c:629 [inline]
sock_sendmsg net/socket.c:639 [inline]
___sys_sendmsg+0xec8/0x1320 net/socket.c:2117
__sys_sendmsg net/socket.c:2155 [inline]
__do_sys_sendmsg net/socket.c:2164 [inline]
__se_sys_sendmsg net/socket.c:2162 [inline]
__x64_sys_sendmsg+0x331/0x460 net/socket.c:2162
do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: fdb694a01f1f ("netfilter: Add fail-open support")
Fixes: 829e17a1a602 ("[NETFILTER]: nfnetlink_queue: allow changing queue length through netlink")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
net/netfilter/nfnetlink_queue_core.c | 3 +++
1 file changed, 3 insertions(+)

--- a/net/netfilter/nfnetlink_queue_core.c
+++ b/net/netfilter/nfnetlink_queue_core.c
@@ -1039,6 +1039,9 @@ nfqnl_recv_unsupp(struct sock *ctnl, str
static const struct nla_policy nfqa_cfg_policy[NFQA_CFG_MAX+1] = {
[NFQA_CFG_CMD] = { .len = sizeof(struct nfqnl_msg_config_cmd) },
[NFQA_CFG_PARAMS] = { .len = sizeof(struct nfqnl_msg_config_params) },
+ [NFQA_CFG_QUEUE_MAXLEN] = { .type = NLA_U32 },
+ [NFQA_CFG_MASK] = { .type = NLA_U32 },
+ [NFQA_CFG_FLAGS] = { .type = NLA_U32 },
};

static const struct nf_queue_handler nfqh = {