| Message ID | 20200713075528.141235-1-chenweilong@huawei.com |
|---|---|
| State | Changes Requested |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net-next] rtnetlink: Fix memory(net_device) leak when ->newlink fails | expand |
From: Weilong Chen <chenweilong@huawei.com> Date: Mon, 13 Jul 2020 15:55:28 +0800 > When vlan_newlink call register_vlan_dev fails, it might return error > with dev->reg_state = NETREG_UNREGISTERED. The rtnl_newlink should > free the memory. But currently rtnl_newlink only free the memory which > state is NETREG_UNINITIALIZED. ... > Reported-by: Hulk Robot <hulkci@huawei.com> > Signed-off-by: Weilong Chen <chenweilong@huawei.com> This needs a Fixes: tag. Also, can't this bug happen in mainline too? It's a bug fix and therefore should target 'net' instead of 'net-next'.
On 2020/7/14 3:02, David Miller wrote: > From: Weilong Chen <chenweilong@huawei.com> > Date: Mon, 13 Jul 2020 15:55:28 +0800 > >> When vlan_newlink call register_vlan_dev fails, it might return error >> with dev->reg_state = NETREG_UNREGISTERED. The rtnl_newlink should >> free the memory. But currently rtnl_newlink only free the memory which >> state is NETREG_UNINITIALIZED. > ... >> Reported-by: Hulk Robot <hulkci@huawei.com> >> Signed-off-by: Weilong Chen <chenweilong@huawei.com> > > This needs a Fixes: tag. > > Also, can't this bug happen in mainline too? It's a bug fix and therefore > should target 'net' instead of 'net-next'. >> . > Yes, it can happend in mainline, I'll send a v2 PATCH.
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 9aedc15736ad..85a4b0101f76 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3343,7 +3343,8 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, */ if (err < 0) { /* If device is not registered at all, free it now */ - if (dev->reg_state == NETREG_UNINITIALIZED) + if (dev->reg_state == NETREG_UNINITIALIZED || + dev->reg_state == NETREG_UNREGISTERED) free_netdev(dev); goto out; }
When vlan_newlink call register_vlan_dev fails, it might return error with dev->reg_state = NETREG_UNREGISTERED. The rtnl_newlink should free the memory. But currently rtnl_newlink only free the memory which state is NETREG_UNINITIALIZED. BUG: memory leak unreferenced object 0xffff8881051de000 (size 4096): comm "syz-executor139", pid 560, jiffies 4294745346 (age 32.445s) hex dump (first 32 bytes): 76 6c 61 6e 32 00 00 00 00 00 00 00 00 00 00 00 vlan2........... 00 45 28 03 81 88 ff ff 00 00 00 00 00 00 00 00 .E(............. backtrace: [<0000000047527e31>] kmalloc_node include/linux/slab.h:578 [inline] [<0000000047527e31>] kvmalloc_node+0x33/0xd0 mm/util.c:574 [<000000002b59e3bc>] kvmalloc include/linux/mm.h:753 [inline] [<000000002b59e3bc>] kvzalloc include/linux/mm.h:761 [inline] [<000000002b59e3bc>] alloc_netdev_mqs+0x83/0xd90 net/core/dev.c:9929 [<000000006076752a>] rtnl_create_link+0x2c0/0xa20 net/core/rtnetlink.c:3067 [<00000000572b3be5>] __rtnl_newlink+0xc9c/0x1330 net/core/rtnetlink.c:3329 [<00000000e84ea553>] rtnl_newlink+0x66/0x90 net/core/rtnetlink.c:3397 [<0000000052c7c0a9>] rtnetlink_rcv_msg+0x540/0x990 net/core/rtnetlink.c:5460 [<000000004b5cb379>] netlink_rcv_skb+0x12b/0x3a0 net/netlink/af_netlink.c:2469 [<00000000c71c20d3>] netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] [<00000000c71c20d3>] netlink_unicast+0x4c6/0x690 net/netlink/af_netlink.c:1329 [<00000000cca72fa9>] netlink_sendmsg+0x735/0xcc0 net/netlink/af_netlink.c:1918 [<000000009221ebf7>] sock_sendmsg_nosec net/socket.c:652 [inline] [<000000009221ebf7>] sock_sendmsg+0x109/0x140 net/socket.c:672 [<000000001c30ffe4>] ____sys_sendmsg+0x5f5/0x780 net/socket.c:2352 [<00000000b71ca6f3>] ___sys_sendmsg+0x11d/0x1a0 net/socket.c:2406 [<0000000007297384>] __sys_sendmsg+0xeb/0x1b0 net/socket.c:2439 [<000000000eb29b11>] do_syscall_64+0x56/0xa0 arch/x86/entry/common.c:359 [<000000006839b4d0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Weilong Chen <chenweilong@huawei.com> --- net/core/rtnetlink.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)