[PATCH 5.9 017/757] net/tls: sendfile fails with ktls offload

Greg Kroah-Hartman
2020-10-27T15:27:03Z

From: Rohit Maheshwari <rohitm@chelsio.com>

[ Upstream commit ea1dd3e9d080c961b9a451130b61c72dc9a5397b ]

At first when sendpage gets called, if there is more data, 'more' in
tls_push_data() gets set which later sets pending_open_record_frags, but
when there is no more data in file left, and last time tls_push_data()
gets called, pending_open_record_frags doesn't get reset. And later when
2 bytes of encrypted alert comes as sendmsg, it first checks for
pending_open_record_frags, and since this is set, it creates a record with
0 data bytes to encrypt, meaning record length is prepend_size + tag_size
only, which causes problem.
We should set/reset pending_open_record_frags based on more bit.

Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/tls/tls_device.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -418,14 +418,14 @@ static int tls_push_data(struct sock *sk
struct tls_context *tls_ctx = tls_get_ctx(sk);
struct tls_prot_info *prot = &tls_ctx->prot_info;
struct tls_offload_context_tx *ctx = tls_offload_ctx_tx(tls_ctx);
- int more = flags & (MSG_SENDPAGE_NOTLAST | MSG_MORE);
struct tls_record_info *record = ctx->open_record;
int tls_push_record_flags;
struct page_frag *pfrag;
size_t orig_size = size;
u32 max_open_record_len;
- int copy, rc = 0;
+ bool more = false;
bool done = false;
+ int copy, rc = 0;
long timeo;

if (flags &
@@ -492,9 +492,8 @@ handle_error:
if (!size) {
last_record:
tls_push_record_flags = flags;
- if (more) {
- tls_ctx->pending_open_record_frags =
- !!record->num_frags;
+ if (flags & (MSG_SENDPAGE_NOTLAST | MSG_MORE)) {
+ more = true;
break;
}

@@ -526,6 +525,8 @@ last_record:
}
} while (!done);

+ tls_ctx->pending_open_record_frags = more;
+
if (orig_size - size > 0)
rc = orig_size - size;