| Message ID | 20210410181732.25995-1-xiyou.wangcong@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [net] smc: disallow TCP_ULP in smc_setsockopt() | expand |
On 10/04/2021 20:17, Cong Wang wrote: > From: Cong Wang <cong.wang@bytedance.com> > > syzbot is able to setup kTLS on an SMC socket, which coincidentally > uses sk_user_data too, later, kTLS treats it as psock so triggers a > refcnt warning. The cause is that smc_setsockopt() simply calls > TCP setsockopt(). I do not think it makes sense to setup kTLS on > top of SMC, so we can just disallow this. > > Reported-and-tested-by: syzbot+b54a1ce86ba4a623b7f0@syzkaller.appspotmail.com > Cc: John Fastabend <john.fastabend@gmail.com> > Cc: Karsten Graul <kgraul@linux.ibm.com> > Signed-off-by: Cong Wang <cong.wang@bytedance.com> > --- > net/smc/af_smc.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c > index 47340b3b514f..0d4d6d28f20c 100644 > --- a/net/smc/af_smc.c > +++ b/net/smc/af_smc.c > @@ -2162,6 +2162,9 @@ static int smc_setsockopt(struct socket *sock, int level, int optname, > struct smc_sock *smc; > int val, rc; > > + if (optname == TCP_ULP) > + return -EOPNOTSUPP; > + > smc = smc_sk(sk); > > /* generic setsockopts reaching us here always apply to the > @@ -2186,7 +2189,6 @@ static int smc_setsockopt(struct socket *sock, int level, int optname, > if (rc || smc->use_fallback) > goto out; > switch (optname) { > - case TCP_ULP: Should'nt it return -EOPNOTSUPP in that case, too? > case TCP_FASTOPEN: > case TCP_FASTOPEN_CONNECT: > case TCP_FASTOPEN_KEY: > -- Karsten (I'm a dude)
On Sun, Apr 11, 2021 at 11:52 PM Karsten Graul <kgraul@linux.ibm.com> wrote: > > > > On 10/04/2021 20:17, Cong Wang wrote: > > From: Cong Wang <cong.wang@bytedance.com> > > > > syzbot is able to setup kTLS on an SMC socket, which coincidentally > > uses sk_user_data too, later, kTLS treats it as psock so triggers a > > refcnt warning. The cause is that smc_setsockopt() simply calls > > TCP setsockopt(). I do not think it makes sense to setup kTLS on > > top of SMC, so we can just disallow this. > > > > Reported-and-tested-by: syzbot+b54a1ce86ba4a623b7f0@syzkaller.appspotmail.com > > Cc: John Fastabend <john.fastabend@gmail.com> > > Cc: Karsten Graul <kgraul@linux.ibm.com> > > Signed-off-by: Cong Wang <cong.wang@bytedance.com> > > --- > > net/smc/af_smc.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c > > index 47340b3b514f..0d4d6d28f20c 100644 > > --- a/net/smc/af_smc.c > > +++ b/net/smc/af_smc.c > > @@ -2162,6 +2162,9 @@ static int smc_setsockopt(struct socket *sock, int level, int optname, > > struct smc_sock *smc; > > int val, rc; > > > > + if (optname == TCP_ULP) > > + return -EOPNOTSUPP; > > + > > smc = smc_sk(sk); > > > > /* generic setsockopts reaching us here always apply to the > > @@ -2186,7 +2189,6 @@ static int smc_setsockopt(struct socket *sock, int level, int optname, > > if (rc || smc->use_fallback) > > goto out; > > switch (optname) { > > - case TCP_ULP: > > Should'nt it return -EOPNOTSUPP in that case, too? I do not think I understand this. In case of TCP_ULP, we will not even reach this switch case after my patch. Thanks.
On 10/04/2021 20:17, Cong Wang wrote: > From: Cong Wang <cong.wang@bytedance.com> > > syzbot is able to setup kTLS on an SMC socket, which coincidentally > uses sk_user_data too, later, kTLS treats it as psock so triggers a > refcnt warning. The cause is that smc_setsockopt() simply calls > TCP setsockopt(). I do not think it makes sense to setup kTLS on > top of SMC, so we can just disallow this. > > Reported-and-tested-by: syzbot+b54a1ce86ba4a623b7f0@syzkaller.appspotmail.com > Cc: John Fastabend <john.fastabend@gmail.com> > Cc: Karsten Graul <kgraul@linux.ibm.com> > Signed-off-by: Cong Wang <cong.wang@bytedance.com> > --- Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 47340b3b514f..0d4d6d28f20c 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -2162,6 +2162,9 @@ static int smc_setsockopt(struct socket *sock, int level, int optname, struct smc_sock *smc; int val, rc; + if (optname == TCP_ULP) + return -EOPNOTSUPP; + smc = smc_sk(sk); /* generic setsockopts reaching us here always apply to the @@ -2186,7 +2189,6 @@ static int smc_setsockopt(struct socket *sock, int level, int optname, if (rc || smc->use_fallback) goto out; switch (optname) { - case TCP_ULP: case TCP_FASTOPEN: case TCP_FASTOPEN_CONNECT: case TCP_FASTOPEN_KEY: