4.20-stable review patch. If anyone has any objections, please let me know.
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From: Willem de Bruijn willemb@google.com
[ Upstream commit 6b8d95f1795c42161dc0984b6863e95d6acf24ed ]
Validate packet socket address length if a length is given. Zero length is equivalent to not setting an address.
Fixes: 99137b7888f4 ("packet: validate address length") Reported-by: Ido Schimmel idosch@idosch.org Signed-off-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 --- net/packet/af_packet.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2625,7 +2625,7 @@ static int tpacket_snd(struct packet_soc sll_addr))) goto out; proto = saddr->sll_protocol; - addr = saddr->sll_addr; + 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; @@ -2825,7 +2825,7 @@ static int packet_snd(struct socket *soc if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr))) goto out; proto = saddr->sll_protocol; - addr = saddr->sll_addr; + 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;