From: Chuck Lever <cel@kernel.org>
A zero-length application_data record decrypts to full_len == 0,
so tls_sw_splice_read() splices zero bytes and returns zero. A zero
return from a splice read means EOF, and the caller tears down a
connection that is still live.
Consume the record and fetch the next one, as tls_sw_read_sock()
does. The cap on consecutive empty records bounds the loop.
When an empty record precedes a close_notify, splice(2) now returns
-EINVAL from the control-record test instead of a false EOF. A
splice that reaches an alert record already reports -EINVAL.
Fixes: c46234ebb4d1 ("tls: RX path for ktls")
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Closes: https://lore.kernel.org/netdev/akaoXcfamBp8_mYe@krikkit/ (local)
Signed-off-by: Chuck Lever <cel@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
Jakub:
- rewrite as a loop to avoid the non-error-handling goto
---
net/tls/tls_sw.c | 48 ++++++++++++++++++++++++++++--------------------
1 file changed, 28 insertions(+), 20 deletions(-)
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index adf3b26b8a75..b05b9e76bd25 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -2044,32 +2044,40 @@ ssize_t tls_sw_splice_read(struct socket *sock, loff_t *ppos,
if (err)
goto splice_read_end;
- if (!skb_queue_empty(&ctx->rx_list)) {
- skb = __skb_dequeue(&ctx->rx_list);
- } else {
- struct tls_decrypt_arg darg;
+ for (;;) {
+ if (!skb_queue_empty(&ctx->rx_list)) {
+ skb = __skb_dequeue(&ctx->rx_list);
+ } else {
+ struct tls_decrypt_arg darg;
- err = tls_rx_rec_wait(sk, nonblock, true, false);
- if (err <= 0)
- goto splice_read_end;
+ err = tls_rx_rec_wait(sk, nonblock, true, false);
+ if (err <= 0)
+ goto splice_read_end;
- memset(&darg.inargs, 0, sizeof(darg.inargs));
+ memset(&darg.inargs, 0, sizeof(darg.inargs));
- err = tls_rx_one_record(sk, NULL, &darg);
- if (err < 0)
- goto splice_read_end;
+ err = tls_rx_one_record(sk, NULL, &darg);
+ if (err < 0)
+ goto splice_read_end;
- tls_rx_rec_done(ctx);
- skb = darg.skb;
- }
+ tls_rx_rec_done(ctx);
+ skb = darg.skb;
+ }
- rxm = strp_msg(skb);
- tlm = tls_msg(skb);
+ rxm = strp_msg(skb);
+ tlm = tls_msg(skb);
- /* splice does not support reading control messages */
- if (tlm->control != TLS_RECORD_TYPE_DATA) {
- err = -EINVAL;
- goto splice_requeue;
+ /* splice does not support reading control messages */
+ if (tlm->control != TLS_RECORD_TYPE_DATA) {
+ err = -EINVAL;
+ goto splice_requeue;
+ }
+
+ /* Splicing zero bytes would read as EOF */
+ if (rxm->full_len)
+ break;
+
+ consume_skb(skb);
}
chunk = min_t(unsigned int, rxm->full_len, len);--
2.56.0