From: Eric Dumazet edumazet@google.com
[ Upstream commit 9bbd917e0bec9aebdbd0c8dbc966caec15eb33e9 ]
There are few cases where the ndo_uninit() handler might be not called if an error happens while device is initialized.
Since vlan_newlink() calls vlan_changelink() before trying to register the netdevice, we need to make sure vlan_dev_uninit() has been called at least once, or we might leak allocated memory.
BUG: memory leak unreferenced object 0xffff888122a206c0 (size 32): comm "syz-executor511", pid 7124, jiffies 4294950399 (age 32.240s) hex dump (first 32 bytes): 00 00 00 00 00 00 61 73 00 00 00 00 00 00 00 00 ......as........ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<000000000eb3bb85>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] [<000000000eb3bb85>] slab_post_alloc_hook mm/slab.h:586 [inline] [<000000000eb3bb85>] slab_alloc mm/slab.c:3320 [inline] [<000000000eb3bb85>] kmem_cache_alloc_trace+0x145/0x2c0 mm/slab.c:3549 [<000000007b99f620>] kmalloc include/linux/slab.h:556 [inline] [<000000007b99f620>] vlan_dev_set_egress_priority+0xcc/0x150 net/8021q/vlan_dev.c:194 [<000000007b0cb745>] vlan_changelink+0xd6/0x140 net/8021q/vlan_netlink.c:126 [<0000000065aba83a>] vlan_newlink+0x135/0x200 net/8021q/vlan_netlink.c:181 [<00000000fb5dd7a2>] __rtnl_newlink+0x89a/0xb80 net/core/rtnetlink.c:3305 [<00000000ae4273a1>] rtnl_newlink+0x4e/0x80 net/core/rtnetlink.c:3363 [<00000000decab39f>] rtnetlink_rcv_msg+0x178/0x4b0 net/core/rtnetlink.c:5424 [<00000000accba4ee>] netlink_rcv_skb+0x61/0x170 net/netlink/af_netlink.c:2477 [<00000000319fe20f>] rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5442 [<00000000d51938dc>] netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] [<00000000d51938dc>] netlink_unicast+0x223/0x310 net/netlink/af_netlink.c:1328 [<00000000e539ac79>] netlink_sendmsg+0x2c0/0x570 net/netlink/af_netlink.c:1917 [<000000006250c27e>] sock_sendmsg_nosec net/socket.c:639 [inline] [<000000006250c27e>] sock_sendmsg+0x54/0x70 net/socket.c:659 [<00000000e2a156d1>] ____sys_sendmsg+0x2d0/0x300 net/socket.c:2330 [<000000008c87466e>] ___sys_sendmsg+0x8a/0xd0 net/socket.c:2384 [<00000000110e3054>] __sys_sendmsg+0x80/0xf0 net/socket.c:2417 [<00000000d71077c8>] __do_sys_sendmsg net/socket.c:2426 [inline] [<00000000d71077c8>] __se_sys_sendmsg net/socket.c:2424 [inline] [<00000000d71077c8>] __x64_sys_sendmsg+0x23/0x30 net/socket.c:2424
Fixe: 07b5b17e157b ("[VLAN]: Use rtnl_link API") Signed-off-by: Eric Dumazet edumazet@google.com Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/8021q/vlan.h | 1 + net/8021q/vlan_dev.c | 3 ++- net/8021q/vlan_netlink.c | 9 +++++---- 3 files changed, 8 insertions(+), 5 deletions(-)
--- a/net/8021q/vlan.h +++ b/net/8021q/vlan.h @@ -114,6 +114,7 @@ int vlan_check_real_dev(struct net_devic void vlan_setup(struct net_device *dev); int register_vlan_dev(struct net_device *dev, struct netlink_ext_ack *extack); void unregister_vlan_dev(struct net_device *dev, struct list_head *head); +void vlan_dev_uninit(struct net_device *dev); bool vlan_dev_inherit_address(struct net_device *dev, struct net_device *real_dev);
--- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -612,7 +612,8 @@ static int vlan_dev_init(struct net_devi return 0; }
-static void vlan_dev_uninit(struct net_device *dev) +/* Note: this function might be called multiple times for the same device. */ +void vlan_dev_uninit(struct net_device *dev) { struct vlan_priority_tci_mapping *pm; struct vlan_dev_priv *vlan = vlan_dev_priv(dev); --- a/net/8021q/vlan_netlink.c +++ b/net/8021q/vlan_netlink.c @@ -181,10 +181,11 @@ static int vlan_newlink(struct net *src_ return -EINVAL;
err = vlan_changelink(dev, tb, data, extack); - if (err < 0) - return err; - - return register_vlan_dev(dev, extack); + if (!err) + err = register_vlan_dev(dev, extack); + if (err) + vlan_dev_uninit(dev); + return err; }
static inline size_t vlan_qos_map_size(unsigned int n)