| Message ID | 20180116133152.24397-1-ilyal@mellanox.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [v2,net,1/1] net/tls: Only attach to sockets in ESTABLISHED state | expand |
From: Ilya Lesokhin <ilyal@mellanox.com> Date: Tue, 16 Jan 2018 15:31:52 +0200 > Calling accept on a TCP socket with a TLS ulp attached results > in two sockets that share the same ulp context. > The ulp context is freed while a socket is destroyed, so > after one of the sockets is released, the second second will > trigger a use after free when it tries to access the ulp context > attached to it. > We restrict the TLS ulp to sockets in ESTABLISHED state > to prevent the scenario above. > > Fixes: 3c4d7559159b ("tls: kernel TLS support") > Reported-by: syzbot+904e7cd6c5c741609228@syzkaller.appspotmail.com > Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com> > --- > v2: Fix typos Applied and queued up for -stable, thanks.
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c index e07ee3ae0023..7b7a70e22d90 100644 --- a/net/tls/tls_main.c +++ b/net/tls/tls_main.c @@ -454,6 +454,15 @@ static int tls_init(struct sock *sk) struct tls_context *ctx; int rc = 0; + /* The TLS ulp is currently supported only for TCP sockets + * in ESTABLISHED state. + * Supporting sockets in LISTEN state will require us + * to modify the accept implementation to clone rather then + * share the ulp context. + */ + if (sk->sk_state != TCP_ESTABLISHED) + return -ENOTSUPP; + /* allocate tls context */ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); if (!ctx) {
Calling accept on a TCP socket with a TLS ulp attached results in two sockets that share the same ulp context. The ulp context is freed while a socket is destroyed, so after one of the sockets is released, the second second will trigger a use after free when it tries to access the ulp context attached to it. We restrict the TLS ulp to sockets in ESTABLISHED state to prevent the scenario above. Fixes: 3c4d7559159b ("tls: kernel TLS support") Reported-by: syzbot+904e7cd6c5c741609228@syzkaller.appspotmail.com Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com> --- v2: Fix typos net/tls/tls_main.c | 9 +++++++++ 1 file changed, 9 insertions(+)