6.16-stable review patch. If anyone has any objections, please let me know.
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From: Jakub Kicinski kuba@kernel.org
commit 62708b9452f8eb77513115b17c4f8d1a22ebf843 upstream.
Each recvmsg() call must process either - only contiguous DATA records (any number of them) - one non-DATA record
If the next record has different type than what has already been processed we break out of the main processing loop. If the record has already been decrypted (which may be the case for TLS 1.3 where we don't know type until decryption) we queue the pending record to the rx_list. Next recvmsg() will pick it up from there.
Queuing the skb to rx_list after zero-copy decrypt is not possible, since in that case we decrypted directly to the user space buffer, and we don't have an skb to queue (darg.skb points to the ciphertext skb for access to metadata like length).
Only data records are allowed zero-copy, and we break the processing loop after each non-data record. So we should never zero-copy and then find out that the record type has changed. The corner case we missed is when the initial record comes from rx_list, and it's zero length.
Reported-by: Muhammad Alifa Ramdhan ramdhan@starlabs.sg Reported-by: Billy Jheng Bing-Jhong billy@starlabs.sg Fixes: 84c61fe1a75b ("tls: rx: do not use the standard strparser") Reviewed-by: Sabrina Dubroca sd@queasysnail.net Link: https://patch.msgid.link/20250820021952.143068-1-kuba@kernel.org Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/tls/tls_sw.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1808,6 +1808,9 @@ int decrypt_skb(struct sock *sk, struct return tls_decrypt_sg(sk, NULL, sgout, &darg); }
+/* All records returned from a recvmsg() call must have the same type. + * 0 is not a valid content type. Use it as "no type reported, yet". + */ static int tls_record_content_type(struct msghdr *msg, struct tls_msg *tlm, u8 *control) { @@ -2051,8 +2054,10 @@ int tls_sw_recvmsg(struct sock *sk, if (err < 0) goto end;
+ /* process_rx_list() will set @control if it processed any records */ copied = err; - if (len <= copied || (copied && control != TLS_RECORD_TYPE_DATA) || rx_more) + if (len <= copied || rx_more || + (control && control != TLS_RECORD_TYPE_DATA)) goto end;
target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);