4.9-stable review patch. If anyone has any objections, please let me know.
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From: Guillaume Nault g.nault@alphalink.fr
[ Upstream commit a49e2f5d5fb141884452ddb428f551b123d436b5 ]
We must validate sockaddr_len, otherwise userspace can pass fewer data than we expect and we end up accessing invalid data.
Fixes: 224cf5ad14c0 ("ppp: Move the PPP drivers") Reported-by: syzbot+4f03bdf92fdf9ef5ddab@syzkaller.appspotmail.com Signed-off-by: Guillaume Nault g.nault@alphalink.fr Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ppp/pppoe.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/drivers/net/ppp/pppoe.c +++ b/drivers/net/ppp/pppoe.c @@ -620,6 +620,10 @@ static int pppoe_connect(struct socket * lock_sock(sk);
error = -EINVAL; + + if (sockaddr_len != sizeof(struct sockaddr_pppox)) + goto end; + if (sp->sa_protocol != PX_PROTO_OE) goto end;