From d5e4d0a5e692a942f0c212e37dc6aeac47ecbdea Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 21 Sep 2020 07:27:20 -0700 Subject: 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 Cc: Paolo Abeni Cc: Christoph Paasch Cc: Mat Martineau Acked-by: Paolo Abeni Signed-off-by: David S. Miller --- net/ipv4/inet_diag.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) (limited to 'net/ipv4/inet_diag.c') diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 4a98dd736270..f1bd95f243b3 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -186,8 +186,8 @@ errout: } 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); -- cgit v1.2.3