| Message ID | 73b14b25ad7741c9ddcef061ab65a9b7ea8811bc.1557506063.git.pabeni@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v3] selinux: do not report error on connect(AF_UNSPEC) | expand |
On Fri, May 10, 2019 at 1:13 PM Paolo Abeni <pabeni@redhat.com> wrote: > calling connect(AF_UNSPEC) on an already connected TCP socket is an > established way to disconnect() such socket. After commit 68741a8adab9 > ("selinux: Fix ltp test connect-syscall failure") it no longer works > and, in the above scenario connect() fails with EAFNOSUPPORT. > > Fix the above explicitly early checking for AF_UNSPEC family, and > returning success in that case. > > Suggested-by: Paul Moore <paul@paul-moore.com> > Fixes: 68741a8adab9 ("selinux: Fix ltp test connect-syscall failure") > Reported-by: Tom Deseyn <tdeseyn@redhat.com> > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > --- > v2 -> v3: > - do the check for AF_UNSPEC at the begining, as suggested by Paul > v1 -> v2: > - avoid validation for AF_UNSPEC > --- > security/selinux/hooks.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) Thanks Paolo, this looks good. It sounded like DaveM wanted this to go to -stable so I'll merge it and mark it as such; I think I will wait until the end of this week just to see if there are any other things which crop up during the merge window. > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index c61787b15f27..3ec702cf46ca 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -4637,6 +4637,14 @@ static int selinux_socket_connect_helper(struct socket *sock, > err = sock_has_perm(sk, SOCKET__CONNECT); > if (err) > return err; > + if (addrlen < offsetofend(struct sockaddr, sa_family)) > + return -EINVAL; > + > + /* connect(AF_UNSPEC) has special handling, as it is a documented > + * way to disconnect the socket > + */ > + if (address->sa_family == AF_UNSPEC) > + return 0; > > /* > * If a TCP, DCCP or SCTP socket, check name_connect permission > @@ -4657,8 +4665,6 @@ static int selinux_socket_connect_helper(struct socket *sock, > * need to check address->sa_family as it is possible to have > * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET. > */ > - if (addrlen < offsetofend(struct sockaddr, sa_family)) > - return -EINVAL; > switch (address->sa_family) { > case AF_INET: > addr4 = (struct sockaddr_in *)address; > -- > 2.20.1
On Mon, May 13, 2019 at 6:50 PM Paul Moore <paul@paul-moore.com> wrote: > On Fri, May 10, 2019 at 1:13 PM Paolo Abeni <pabeni@redhat.com> wrote: > > calling connect(AF_UNSPEC) on an already connected TCP socket is an > > established way to disconnect() such socket. After commit 68741a8adab9 > > ("selinux: Fix ltp test connect-syscall failure") it no longer works > > and, in the above scenario connect() fails with EAFNOSUPPORT. > > > > Fix the above explicitly early checking for AF_UNSPEC family, and > > returning success in that case. > > > > Suggested-by: Paul Moore <paul@paul-moore.com> > > Fixes: 68741a8adab9 ("selinux: Fix ltp test connect-syscall failure") > > Reported-by: Tom Deseyn <tdeseyn@redhat.com> > > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > > --- > > v2 -> v3: > > - do the check for AF_UNSPEC at the begining, as suggested by Paul > > v1 -> v2: > > - avoid validation for AF_UNSPEC > > --- > > security/selinux/hooks.c | 10 ++++++++-- > > 1 file changed, 8 insertions(+), 2 deletions(-) > > Thanks Paolo, this looks good. It sounded like DaveM wanted this to > go to -stable so I'll merge it and mark it as such; I think I will > wait until the end of this week just to see if there are any other > things which crop up during the merge window. Just a quick follow-up, I just merged this into selinux/stable-5.2 and assuming the build/test runs clean overnight I'll send this to Linus tomorrow. Thanks again for the report and the fix.
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index c61787b15f27..3ec702cf46ca 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4637,6 +4637,14 @@ static int selinux_socket_connect_helper(struct socket *sock, err = sock_has_perm(sk, SOCKET__CONNECT); if (err) return err; + if (addrlen < offsetofend(struct sockaddr, sa_family)) + return -EINVAL; + + /* connect(AF_UNSPEC) has special handling, as it is a documented + * way to disconnect the socket + */ + if (address->sa_family == AF_UNSPEC) + return 0; /* * If a TCP, DCCP or SCTP socket, check name_connect permission @@ -4657,8 +4665,6 @@ static int selinux_socket_connect_helper(struct socket *sock, * need to check address->sa_family as it is possible to have * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET. */ - if (addrlen < offsetofend(struct sockaddr, sa_family)) - return -EINVAL; switch (address->sa_family) { case AF_INET: addr4 = (struct sockaddr_in *)address;
calling connect(AF_UNSPEC) on an already connected TCP socket is an established way to disconnect() such socket. After commit 68741a8adab9 ("selinux: Fix ltp test connect-syscall failure") it no longer works and, in the above scenario connect() fails with EAFNOSUPPORT. Fix the above explicitly early checking for AF_UNSPEC family, and returning success in that case. Suggested-by: Paul Moore <paul@paul-moore.com> Fixes: 68741a8adab9 ("selinux: Fix ltp test connect-syscall failure") Reported-by: Tom Deseyn <tdeseyn@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- v2 -> v3: - do the check for AF_UNSPEC at the begining, as suggested by Paul v1 -> v2: - avoid validation for AF_UNSPEC --- security/selinux/hooks.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)