[MPTCP][PATCH mptcp-next] mptcp: free entry when release_work allocation fails

From: Geliang Tang <geliangtang@gmail.com>
To: mptcp@lists.linux.dev, geliangtang@gmail.com
Cc: Geliang Tang <geliangtang@xiaomi.com>
Subject: [MPTCP][PATCH mptcp-next] mptcp: free entry when release_work allocation fails
Date: Thu, 12 Aug 2021 11:37:57 +0800	[thread overview]
Message-ID: <cba51616ec99f106c50dd7b0560450812adcd581.1628739395.git.geliangtang@xiaomi.com> (raw)

From: Geliang Tang <geliangtang@xiaomi.com>

This patch fixed this syzkaller error:

 BUG: memory leak
 unreferenced object 0xffff88810680ea00 (size 64):
   comm "syz-executor.6", pid 6191, jiffies 4295756280 (age 24.138s)
   hex dump (first 32 bytes):
     58 75 7d 3c 80 88 ff ff 22 01 00 00 00 00 ad de  Xu}<....".......
     01 00 02 00 00 00 00 00 ac 1e 00 07 00 00 00 00  ................
   backtrace:
     [<0000000072a9f72a>] kmalloc include/linux/slab.h:591 [inline]
     [<0000000072a9f72a>] mptcp_nl_cmd_add_addr+0x287/0x9f0 net/mptcp/pm_netlink.c:1170
     [<00000000f6e931bf>] genl_family_rcv_msg_doit.isra.0+0x225/0x340 net/netlink/genetlink.c:731
     [<00000000f1504a2c>] genl_family_rcv_msg net/netlink/genetlink.c:775 [inline]
     [<00000000f1504a2c>] genl_rcv_msg+0x341/0x5b0 net/netlink/genetlink.c:792
     [<0000000097e76f6a>] netlink_rcv_skb+0x148/0x430 net/netlink/af_netlink.c:2504
     [<00000000ceefa2b8>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:803
     [<000000008ff91aec>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
     [<000000008ff91aec>] netlink_unicast+0x537/0x750 net/netlink/af_netlink.c:1340
     [<0000000041682c35>] netlink_sendmsg+0x846/0xd80 net/netlink/af_netlink.c:1929
     [<00000000df3aa8e7>] sock_sendmsg_nosec net/socket.c:704 [inline]
     [<00000000df3aa8e7>] sock_sendmsg+0x14e/0x190 net/socket.c:724
     [<000000002154c54c>] ____sys_sendmsg+0x709/0x870 net/socket.c:2403
     [<000000001aab01d7>] ___sys_sendmsg+0xff/0x170 net/socket.c:2457
     [<00000000fa3b1446>] __sys_sendmsg+0xe5/0x1b0 net/socket.c:2486
     [<00000000db2ee9c7>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
     [<00000000db2ee9c7>] do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
     [<000000005873517d>] entry_SYSCALL_64_after_hwframe+0x44/0xae

 BUG: leak checking failed

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/223
Fixes: 1729cf186d8a5 (mptcp: create the listening socket for new port)
Signed-off-by: Geliang Tang <geliangtang@xiaomi.com>
---
 net/mptcp/pm_netlink.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 371607dc6ff7..184a75e1c8ec 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1324,6 +1324,8 @@ static void mptcp_pm_free_addr_entry(struct mptcp_pm_addr_entry *entry)
 		INIT_RCU_WORK(&w->rwork, mptcp_pm_release_addr_entry);
 		w->entry = entry;
 		queue_rcu_work(system_wq, &w->rwork);
+	} else {
+		kfree(entry);
 	}
 }
 
-- 
2.31.1

