tls: splice_read: fix record type check

stable inclusion
from stable-v5.10.83
commit 22156242b1042d5cce74f1bd20db541abdd2ecd7
bugzilla: 185879 https://gitee.com/openeuler/kernel/issues/I4QUVG

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=22156242b1042d5cce74f1bd20db541abdd2ecd7

--------------------------------

[ Upstream commit 520493f6 ]

We don't support splicing control records. TLS 1.3 changes moved
the record type check into the decrypt if(). The skb may already
be decrypted and still be an alert.

Note that decrypt_skb_update() is idempotent and updates ctx->decrypted
so the if() is pointless.

Reorder the check for decryption errors with the content type check
while touching them. This part is not really a bug, because if
decryption failed in TLS 1.3 content type will be DATA, and for
TLS 1.2 it will be correct. Nevertheless its strange to touch output
before checking if the function has failed.

Fixes: fedf201e ("net: tls: Refactor control message handling on recv")
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

net/tls/tls_sw.c

@@ -2007,21 +2007,18 @@ ssize_t tls_sw_splice_read(struct socket *sock,  loff_t *ppos,
 	if (!skb)
 		goto splice_read_end;
 
-	if (!ctx->decrypted) {
-		err = decrypt_skb_update(sk, skb, NULL, &chunk, &zc, false);
-
-		/* splice does not support reading control messages */
-		if (ctx->control != TLS_RECORD_TYPE_DATA) {
-			err = -EINVAL;
-			goto splice_read_end;
-		}
+	err = decrypt_skb_update(sk, skb, NULL, &chunk, &zc, false);
+	if (err < 0) {
+		tls_err_abort(sk, -EBADMSG);
+		goto splice_read_end;
+	}
 
-		if (err < 0) {
-			tls_err_abort(sk, -EBADMSG);
-			goto splice_read_end;
-		}
-		ctx->decrypted = 1;
+	/* splice does not support reading control messages */
+	if (ctx->control != TLS_RECORD_TYPE_DATA) {
+		err = -EINVAL;
+		goto splice_read_end;
 	}
+
 	rxm = strp_msg(skb);
 
 	chunk = min_t(unsigned int, rxm->full_len, len);