[PATCH net] calipso: Fix memory leak in netlbl_calipso_add_pass()

[Gavrilov Ilia]

If IPv6 support is disabled at boot (ipv6.disable=1),
the calipso_init() -> netlbl_calipso_ops_register() function isn't called,
and the netlbl_calipso_ops_get() function always returns NULL.
In this case, the netlbl_calipso_add_pass() function allocates memory
for the doi_def variable but doesn't free it with the calipso_doi_free().

BUG: memory leak
unreferenced object 0xffff888011d68180 (size 64):
  comm "syz-executor.1", pid 10746, jiffies 4295410986 (age 17.928s)
  hex dump (first 32 bytes):
    00 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000730d8770>] kmalloc include/linux/slab.h:552 [inline]
    [<00000000730d8770>] netlbl_calipso_add_pass net/netlabel/netlabel_calipso.c:76 [inline]
    [<00000000730d8770>] netlbl_calipso_add+0x22e/0x4f0 net/netlabel/netlabel_calipso.c:111
    [<0000000002e662c0>] genl_family_rcv_msg_doit+0x22f/0x330 net/netlink/genetlink.c:739
    [<00000000a08d6d74>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
    [<00000000a08d6d74>] genl_rcv_msg+0x341/0x5a0 net/netlink/genetlink.c:800
    [<0000000098399a97>] netlink_rcv_skb+0x14d/0x440 net/netlink/af_netlink.c:2515
    [<00000000ff7db83b>] genl_rcv+0x29/0x40 net/netlink/genetlink.c:811
    [<000000000cf53b8c>] netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
    [<000000000cf53b8c>] netlink_unicast+0x54b/0x800 net/netlink/af_netlink.c:1339
    [<00000000d78cd38b>] netlink_sendmsg+0x90a/0xdf0 net/netlink/af_netlink.c:1934
    [<000000008328a57f>] sock_sendmsg_nosec net/socket.c:651 [inline]
    [<000000008328a57f>] sock_sendmsg+0x157/0x190 net/socket.c:671
    [<000000007b65a1b5>] ____sys_sendmsg+0x712/0x870 net/socket.c:2342
    [<0000000083da800e>] ___sys_sendmsg+0xf8/0x170 net/socket.c:2396
    [<000000004a9b827f>] __sys_sendmsg+0xea/0x1b0 net/socket.c:2429
    [<0000000061b64d3a>] do_syscall_64+0x30/0x40 arch/x86/entry/common.c:46
    [<00000000a1265347>] entry_SYSCALL_64_after_hwframe+0x61/0xc6

Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with Syzkaller

Fixes: cb72d38211ea ("netlabel: Initial support for the CALIPSO netlink protocol.")
Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov at infotecs.ru>
---
 net/netlabel/netlabel_calipso.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/netlabel/netlabel_calipso.c b/net/netlabel/netlabel_calipso.c
index f1d5b8465217..76ae57c4df90 100644
--- a/net/netlabel/netlabel_calipso.c
+++ b/net/netlabel/netlabel_calipso.c
@@ -423,6 +423,8 @@ void calipso_doi_free(struct calipso_doi *doi_def)
 
 	if (ops)
 		ops->doi_free(doi_def);
+	else
+		kfree(doi_def);
 }
 
 /**
-- 
2.39.2