packet: Do not leak dev refcounts on error exit

BugLink: https://bugs.launchpad.net/bugs/1837477
[ Upstream commit d972f3dce8d161e2142da0ab1ef25df00e2f21a9 ]

'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 <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index a17fc9574d1894f5dc501ae7ca1f35257dc50b44..c969d8c0ead6f5390c2c4dc26cf40ddc6305b48c 100644 (file)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2656,7 +2656,7 @@ 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;
@@ -2856,7 +2856,7 @@ 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;