[PATCH 4.9 11/96] net-sysfs: Fix mem leak in netdev_register_kobject

From: Greg Kroah-Hartman
Date: Tue Mar 12 2019 - 13:22:55 EST

4.9-stable review patch. If anyone has any objections, please let me know.


From: YueHaibing <yuehaibing@xxxxxxxxxx>

[ Upstream commit 895a5e96dbd6386c8e78e5b78e067dcc67b7f0ab ]

syzkaller report this:
BUG: memory leak
unreferenced object 0xffff88837a71a500 (size 256):
comm "syz-executor.2", pid 9770, jiffies 4297825125 (age 17.843s)
hex dump (first 32 bytes):
00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
ff ff ff ff ff ff ff ff 20 c0 ef 86 ff ff ff ff ........ .......
[<00000000db12624b>] netdev_register_kobject+0x124/0x2e0 net/core/net-sysfs.c:1751
[<00000000dc49a994>] register_netdevice+0xcc1/0x1270 net/core/dev.c:8516
[<00000000e5f3fea0>] tun_set_iff drivers/net/tun.c:2649 [inline]
[<00000000e5f3fea0>] __tun_chr_ioctl+0x2218/0x3d20 drivers/net/tun.c:2883
[<000000001b8ac127>] vfs_ioctl fs/ioctl.c:46 [inline]
[<000000001b8ac127>] do_vfs_ioctl+0x1a5/0x10e0 fs/ioctl.c:690
[<0000000079b269f8>] ksys_ioctl+0x89/0xa0 fs/ioctl.c:705
[<00000000de649beb>] __do_sys_ioctl fs/ioctl.c:712 [inline]
[<00000000de649beb>] __se_sys_ioctl fs/ioctl.c:710 [inline]
[<00000000de649beb>] __x64_sys_ioctl+0x74/0xb0 fs/ioctl.c:710
[<000000007ebded1e>] do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290
[<00000000db315d36>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[<00000000115be9bb>] 0xffffffffffffffff

It should call kset_unregister to free 'dev->queues_kset'
in error path of register_queue_kobjects, otherwise will cause a mem leak.

Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Fixes: 1d24eb4815d1 ("xps: Transmit Packet Steering")
Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
net/core/net-sysfs.c | 3 +++
1 file changed, 3 insertions(+)

--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -1380,6 +1380,9 @@ static int register_queue_kobjects(struc
netdev_queue_update_kobjects(dev, txq, 0);
net_rx_queue_update_kobjects(dev, rxq, 0);
+ kset_unregister(dev->queues_kset);
return error;