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Message-Id: <20200921142720.2328827-1-edumazet@google.com>
Date: Mon, 21 Sep 2020 07:27:20 -0700
From: Eric Dumazet <edumazet@...gle.com>
To: "David S . Miller" <davem@...emloft.net>
Cc: netdev <netdev@...r.kernel.org>,
Eric Dumazet <edumazet@...gle.com>,
Eric Dumazet <eric.dumazet@...il.com>,
Paolo Abeni <pabeni@...hat.com>,
Christoph Paasch <cpaasch@...le.com>,
Mat Martineau <mathew.j.martineau@...ux.intel.com>
Subject: [PATCH net] inet_diag: validate INET_DIAG_REQ_PROTOCOL attribute
User space could send an invalid INET_DIAG_REQ_PROTOCOL attribute
as caught by syzbot.
BUG: KMSAN: uninit-value in inet_diag_lock_handler net/ipv4/inet_diag.c:55 [inline]
BUG: KMSAN: uninit-value in __inet_diag_dump+0x58c/0x720 net/ipv4/inet_diag.c:1147
CPU: 0 PID: 8505 Comm: syz-executor174 Not tainted 5.9.0-rc4-syzkaller #0
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+0x21c/0x280 lib/dump_stack.c:118
kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:122
__msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:219
inet_diag_lock_handler net/ipv4/inet_diag.c:55 [inline]
__inet_diag_dump+0x58c/0x720 net/ipv4/inet_diag.c:1147
inet_diag_dump_compat+0x2a5/0x380 net/ipv4/inet_diag.c:1254
netlink_dump+0xb73/0x1cb0 net/netlink/af_netlink.c:2246
__netlink_dump_start+0xcf2/0xea0 net/netlink/af_netlink.c:2354
netlink_dump_start include/linux/netlink.h:246 [inline]
inet_diag_rcv_msg_compat+0x5da/0x6c0 net/ipv4/inet_diag.c:1288
sock_diag_rcv_msg+0x24f/0x620 net/core/sock_diag.c:256
netlink_rcv_skb+0x6d7/0x7e0 net/netlink/af_netlink.c:2470
sock_diag_rcv+0x63/0x80 net/core/sock_diag.c:275
netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
netlink_unicast+0x11c8/0x1490 net/netlink/af_netlink.c:1330
netlink_sendmsg+0x173a/0x1840 net/netlink/af_netlink.c:1919
sock_sendmsg_nosec net/socket.c:651 [inline]
sock_sendmsg net/socket.c:671 [inline]
____sys_sendmsg+0xc82/0x1240 net/socket.c:2353
___sys_sendmsg net/socket.c:2407 [inline]
__sys_sendmsg+0x6d1/0x820 net/socket.c:2440
__do_sys_sendmsg net/socket.c:2449 [inline]
__se_sys_sendmsg+0x97/0xb0 net/socket.c:2447
__x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447
do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x441389
Code: e8 fc ab 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 1b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff3b02ce98 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441389
RDX: 0000000000000000 RSI: 0000000020001500 RDI: 0000000000000003
RBP: 00000000006cb018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000402130
R13: 00000000004021c0 R14: 0000000000000000 R15: 0000000000000000
Uninit was created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:143 [inline]
kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:126
kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80
slab_alloc_node mm/slub.c:2907 [inline]
__kmalloc_node_track_caller+0x9aa/0x12f0 mm/slub.c:4511
__kmalloc_reserve net/core/skbuff.c:142 [inline]
__alloc_skb+0x35f/0xb30 net/core/skbuff.c:210
alloc_skb include/linux/skbuff.h:1094 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1176 [inline]
netlink_sendmsg+0xdb9/0x1840 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:651 [inline]
sock_sendmsg net/socket.c:671 [inline]
____sys_sendmsg+0xc82/0x1240 net/socket.c:2353
___sys_sendmsg net/socket.c:2407 [inline]
__sys_sendmsg+0x6d1/0x820 net/socket.c:2440
__do_sys_sendmsg net/socket.c:2449 [inline]
__se_sys_sendmsg+0x97/0xb0 net/socket.c:2447
__x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447
do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: 3f935c75eb52 ("inet_diag: support for wider protocol numbers")
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
Cc: Paolo Abeni <pabeni@...hat.com>
Cc: Christoph Paasch <cpaasch@...le.com>
Cc: Mat Martineau <mathew.j.martineau@...ux.intel.com>
---
net/ipv4/inet_diag.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 4a98dd7362702c32620638227c19bf986551d792..f1bd95f243b3065b705b0e5ccff3acbc5cd21127 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -186,8 +186,8 @@ int inet_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb,
}
EXPORT_SYMBOL_GPL(inet_diag_msg_attrs_fill);
-static void inet_diag_parse_attrs(const struct nlmsghdr *nlh, int hdrlen,
- struct nlattr **req_nlas)
+static int inet_diag_parse_attrs(const struct nlmsghdr *nlh, int hdrlen,
+ struct nlattr **req_nlas)
{
struct nlattr *nla;
int remaining;
@@ -195,9 +195,13 @@ static void inet_diag_parse_attrs(const struct nlmsghdr *nlh, int hdrlen,
nlmsg_for_each_attr(nla, nlh, hdrlen, remaining) {
int type = nla_type(nla);
+ if (type == INET_DIAG_REQ_PROTOCOL && nla_len(nla) != sizeof(u32))
+ return -EINVAL;
+
if (type < __INET_DIAG_REQ_MAX)
req_nlas[type] = nla;
}
+ return 0;
}
static int inet_diag_get_protocol(const struct inet_diag_req_v2 *req,
@@ -574,7 +578,10 @@ static int inet_diag_cmd_exact(int cmd, struct sk_buff *in_skb,
int err, protocol;
memset(&dump_data, 0, sizeof(dump_data));
- inet_diag_parse_attrs(nlh, hdrlen, dump_data.req_nlas);
+ err = inet_diag_parse_attrs(nlh, hdrlen, dump_data.req_nlas);
+ if (err)
+ return err;
+
protocol = inet_diag_get_protocol(req, &dump_data);
handler = inet_diag_lock_handler(protocol);
@@ -1180,8 +1187,11 @@ static int __inet_diag_dump_start(struct netlink_callback *cb, int hdrlen)
if (!cb_data)
return -ENOMEM;
- inet_diag_parse_attrs(nlh, hdrlen, cb_data->req_nlas);
-
+ err = inet_diag_parse_attrs(nlh, hdrlen, cb_data->req_nlas);
+ if (err) {
+ kfree(cb_data);
+ return err;
+ }
nla = cb_data->inet_diag_nla_bc;
if (nla) {
err = inet_diag_bc_audit(nla, skb);
--
2.28.0.681.g6f77f65b4e-goog
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