On Fri, Oct 04, 2024 at 12:30:02AM +0300, Mikhail Ivanov wrote: > On 10/3/2024 8:45 PM, Mickaël Salaün wrote: > > Please also add Matthieu in Cc for the network patch series. > > > > On Thu, Oct 03, 2024 at 10:39:31PM +0800, Mikhail Ivanov wrote: > > > Do not check TCP access right if socket protocol is not IPPROTO_TCP. > > > LANDLOCK_ACCESS_NET_BIND_TCP and LANDLOCK_ACCESS_NET_CONNECT_TCP > > > should not restrict bind(2) and connect(2) for non-TCP protocols > > > (SCTP, MPTCP, SMC). > > > > > > Closes: https://github.com/landlock-lsm/linux/issues/40 > > > Fixes: fff69fb03dde ("landlock: Support network rules with TCP bind and connect") > > > Signed-off-by: Mikhail Ivanov <ivanov.mikhail1@xxxxxxxxxxxxxxxxxxx> > > > --- > > > security/landlock/net.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/security/landlock/net.c b/security/landlock/net.c > > > index bc3d943a7118..6f59dd98bb13 100644 > > > --- a/security/landlock/net.c > > > +++ b/security/landlock/net.c > > > @@ -68,7 +68,7 @@ static int current_check_access_socket(struct socket *const sock, > > > return -EACCES; > > > /* Checks if it's a (potential) TCP socket. */ > > > > We can extend this comment to explain that we don't use sk_is_tcp() > > because we need to handle the AF_UNSPEC case. > > Indeed, I'll do this. > > > > > > - if (sock->type != SOCK_STREAM) > > > + if (sock->type != SOCK_STREAM || sock->sk->sk_protocol != IPPROTO_TCP) > > > > I think we should check sock->sk->sk_type instead of sock->type (even if > > it should be the same). To make it simpler, we should only use sk in > > current_check_access_socket(): > > struct sock *sk = sock->sk; > > Agreed. > > > > > Could you please also do s/__sk_common\.skc_/sk_/g ? > > Ofc > > Btw, there is probably incorrect read of skc_family in this function > [1]. I'll add READ_ONCE for sk->sk_family. > > [1] https://lore.kernel.org/all/20240202095404.183274-1-edumazet@xxxxxxxxxx/ I think it should not be a bug with the current code (IPv6 -> IPV4, and socket vs. sock) but we should indeed use READ_ONCE() (and add this link to the commit message). > > > > > > return 0; > > > /* Checks for minimal header length to safely read sa_family. */ > > > -- > > > 2.34.1 > > > > > > >
