| Message ID | 1605413760-21153-1-git-send-email-vfedorenko@novek.ru |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [net,v2] net/tls: fix corrupted data in recvmsg | expand |
On Sun, 15 Nov 2020 07:16:00 +0300 Vadim Fedorenko wrote: > If tcp socket has more data than Encrypted Handshake Message then > tls_sw_recvmsg will try to decrypt next record instead of returning > full control message to userspace as mentioned in comment. The next > message - usually Application Data - gets corrupted because it uses > zero copy for decryption that's why the data is not stored in skb > for next iteration. Revert check to not decrypt next record if > current is not Application Data. > > Fixes: 692d7b5d1f91 ("tls: Fix recvmsg() to be able to peek across multiple records") > Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru> > --- > net/tls/tls_sw.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c > index 95ab5545..2fe9e2c 100644 > --- a/net/tls/tls_sw.c > +++ b/net/tls/tls_sw.c > @@ -1913,7 +1913,7 @@ int tls_sw_recvmsg(struct sock *sk, > * another message type > */ > msg->msg_flags |= MSG_EOR; > - if (ctx->control != TLS_RECORD_TYPE_DATA) > + if (control != TLS_RECORD_TYPE_DATA) Sorry I wasn't clear enough, should this be: if (ctx->control != control) ? Otherwise if we get a control record first and then data record the code will collapse them, which isn't correct, right? > goto recv_end; > } else { > break;
On 17.11.2020 00:26, Jakub Kicinski wrote: > On Sun, 15 Nov 2020 07:16:00 +0300 Vadim Fedorenko wrote: >> If tcp socket has more data than Encrypted Handshake Message then >> tls_sw_recvmsg will try to decrypt next record instead of returning >> full control message to userspace as mentioned in comment. The next >> message - usually Application Data - gets corrupted because it uses >> zero copy for decryption that's why the data is not stored in skb >> for next iteration. Revert check to not decrypt next record if >> current is not Application Data. >> >> Fixes: 692d7b5d1f91 ("tls: Fix recvmsg() to be able to peek across multiple records") >> Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru> >> --- >> net/tls/tls_sw.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c >> index 95ab5545..2fe9e2c 100644 >> --- a/net/tls/tls_sw.c >> +++ b/net/tls/tls_sw.c >> @@ -1913,7 +1913,7 @@ int tls_sw_recvmsg(struct sock *sk, >> * another message type >> */ >> msg->msg_flags |= MSG_EOR; >> - if (ctx->control != TLS_RECORD_TYPE_DATA) >> + if (control != TLS_RECORD_TYPE_DATA) > Sorry I wasn't clear enough, should this be: > > if (ctx->control != control) > > ? Otherwise if we get a control record first and then data record > the code will collapse them, which isn't correct, right? > >> goto recv_end; >> } else { >> break; I think you mean when ctx->control is control record and control is data record. In this case control message will be decrypted without zero copy and will be stored in skb for the next recvmsg, but will not be returned together with data message. This behavior is the same as for TLSv1.3 when record type is known only after decrypting. But if we want completely different flow for TLSv1.2 and TLSv1.3 then changing to check difference in message types makes sense.
On Tue, 17 Nov 2020 00:45:11 +0000 Vadim Fedorenko wrote: > On 17.11.2020 00:26, Jakub Kicinski wrote: > > On Sun, 15 Nov 2020 07:16:00 +0300 Vadim Fedorenko wrote: > >> If tcp socket has more data than Encrypted Handshake Message then > >> tls_sw_recvmsg will try to decrypt next record instead of returning > >> full control message to userspace as mentioned in comment. The next > >> message - usually Application Data - gets corrupted because it uses > >> zero copy for decryption that's why the data is not stored in skb > >> for next iteration. Revert check to not decrypt next record if > >> current is not Application Data. > >> > >> Fixes: 692d7b5d1f91 ("tls: Fix recvmsg() to be able to peek across multiple records") > >> Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru> > >> --- > >> net/tls/tls_sw.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c > >> index 95ab5545..2fe9e2c 100644 > >> --- a/net/tls/tls_sw.c > >> +++ b/net/tls/tls_sw.c > >> @@ -1913,7 +1913,7 @@ int tls_sw_recvmsg(struct sock *sk, > >> * another message type > >> */ > >> msg->msg_flags |= MSG_EOR; > >> - if (ctx->control != TLS_RECORD_TYPE_DATA) > >> + if (control != TLS_RECORD_TYPE_DATA) > > Sorry I wasn't clear enough, should this be: > > > > if (ctx->control != control) > > > > ? Otherwise if we get a control record first and then data record > > the code will collapse them, which isn't correct, right? > > > >> goto recv_end; > >> } else { > >> break; > I think you mean when ctx->control is control record and control is > data record. Yup. > In this case control message will be decrypted without > zero copy and will be stored in skb for the next recvmsg, but will > not be returned together with data message. Could you point me to a line which breaks the loop in that case? > This behavior is the same > as for TLSv1.3 when record type is known only after decrypting. > But if we want completely different flow for TLSv1.2 and TLSv1.3 > then changing to check difference in message types makes sense.
On 17.11.2020 00:54, Jakub Kicinski wrote: > On Tue, 17 Nov 2020 00:45:11 +0000 Vadim Fedorenko wrote: >> On 17.11.2020 00:26, Jakub Kicinski wrote: >>> On Sun, 15 Nov 2020 07:16:00 +0300 Vadim Fedorenko wrote: >>>> If tcp socket has more data than Encrypted Handshake Message then >>>> tls_sw_recvmsg will try to decrypt next record instead of returning >>>> full control message to userspace as mentioned in comment. The next >>>> message - usually Application Data - gets corrupted because it uses >>>> zero copy for decryption that's why the data is not stored in skb >>>> for next iteration. Revert check to not decrypt next record if >>>> current is not Application Data. >>>> >>>> Fixes: 692d7b5d1f91 ("tls: Fix recvmsg() to be able to peek across multiple records") >>>> Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru> >>>> --- >>>> net/tls/tls_sw.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c >>>> index 95ab5545..2fe9e2c 100644 >>>> --- a/net/tls/tls_sw.c >>>> +++ b/net/tls/tls_sw.c >>>> @@ -1913,7 +1913,7 @@ int tls_sw_recvmsg(struct sock *sk, >>>> * another message type >>>> */ >>>> msg->msg_flags |= MSG_EOR; >>>> - if (ctx->control != TLS_RECORD_TYPE_DATA) >>>> + if (control != TLS_RECORD_TYPE_DATA) >>> Sorry I wasn't clear enough, should this be: >>> >>> if (ctx->control != control) >>> >>> ? Otherwise if we get a control record first and then data record >>> the code will collapse them, which isn't correct, right? >>> >>>> goto recv_end; >>>> } else { >>>> break; >> I think you mean when ctx->control is control record and control is >> data record. > Yup. > >> In this case control message will be decrypted without >> zero copy and will be stored in skb for the next recvmsg, but will >> not be returned together with data message. > Could you point me to a line which breaks the loop in that case? > Sure! if (!control) control = tlm->control; else if (control != tlm->control) goto recv_end; In that case control != tlm->control Variable control is set only once and never changes again. >> This behavior is the same >> as for TLSv1.3 when record type is known only after decrypting. >> But if we want completely different flow for TLSv1.2 and TLSv1.3 >> then changing to check difference in message types makes sense.
On Tue, 17 Nov 2020 00:59:54 +0000 Vadim Fedorenko wrote: > >>> Sorry I wasn't clear enough, should this be: > >>> > >>> if (ctx->control != control) > >>> > >>> ? Otherwise if we get a control record first and then data record > >>> the code will collapse them, which isn't correct, right? > >>> > >>>> goto recv_end; > >>>> } else { > >>>> break; > >> I think you mean when ctx->control is control record and control is > >> data record. > > Yup. > > > >> In this case control message will be decrypted without > >> zero copy and will be stored in skb for the next recvmsg, but will > >> not be returned together with data message. > > Could you point me to a line which breaks the loop in that case? > > > Sure! > > if (!control) > control = tlm->control; > else if (control != tlm->control) > goto recv_end; > > > In that case control != tlm->control > Variable control is set only once and never changes again. You're right! Applied, thanks!
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 95ab5545..2fe9e2c 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1913,7 +1913,7 @@ int tls_sw_recvmsg(struct sock *sk, * another message type */ msg->msg_flags |= MSG_EOR; - if (ctx->control != TLS_RECORD_TYPE_DATA) + if (control != TLS_RECORD_TYPE_DATA) goto recv_end; } else { break;
If tcp socket has more data than Encrypted Handshake Message then tls_sw_recvmsg will try to decrypt next record instead of returning full control message to userspace as mentioned in comment. The next message - usually Application Data - gets corrupted because it uses zero copy for decryption that's why the data is not stored in skb for next iteration. Revert check to not decrypt next record if current is not Application Data. Fixes: 692d7b5d1f91 ("tls: Fix recvmsg() to be able to peek across multiple records") Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru> --- net/tls/tls_sw.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)