[PATCH] packet: Do not leak dev refcounts on error exit

[Jason Gunthorpe]

'dev' is non NULL when the addr_len check triggers so it must goto a label
that does the dev_put otherwise dev will have a leaked refcount.

This bug causes the ib_ipoib module to become unloadable when using
systemd-network as it triggers this check on InfiniBand links.

Fixes: 99137b7888f4 ("packet: validate address length")
Reported-by: Leon Romanovsky <leo...@mellanox.com>
Signed-off-by: Jason Gunthorpe <j...@mellanox.com>
---
 net/packet/af_packet.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

This patch should go to -rc please. Thanks

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index eedacdebcd4c61..d0945253f43b3e 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2628,7 +2628,7 @@ static int tpacket_snd(struct packet_sock *po, struct 
msghdr *msg)
                addr    = saddr->sll_halen ? saddr->sll_addr : NULL;
                dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
                if (addr && dev && saddr->sll_halen < dev->addr_len)
-                       goto out;
+                       goto out_put;
        }
 
        err = -ENXIO;
@@ -2828,7 +2828,7 @@ static int packet_snd(struct socket *sock, struct msghdr 
*msg, size_t len)
                addr    = saddr->sll_halen ? saddr->sll_addr : NULL;
                dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
                if (addr && dev && saddr->sll_halen < dev->addr_len)
-                       goto out;
+                       goto out_unlock;
        }
 
        err = -ENXIO;
-- 
2.20.1